General:

Fix script export if many or large scripts are installed
Make @match hostname and scheme case insensitive by default
Update ESLint
Use ES2020 for linting if supported by browser
Experimental window.onurlchange support
Disable automatic script update on script modification

Locales:

Update Arabic locale | thanks to naqqo6i
Update Indonesian locale | thanks to ReksaTresna
Update Japanese locale | thanks to shirayuki

General:
Fix GM_xhr exceptions related to responseType 'document' and 'text'
Fix fetch-based GM_xhr.details.revalidate
Improve @connect permission request handling
Fix GM.notification promise never being resolved
Fix GM_xhr.abort and GM_download.abort
Fix setting GM_download.details.headers

Firefox:
Enable @run-at context-menu
Fix issues if browser is started in private mode
Fix extension shortcut support

Sync:
Improve OneDrive request error handling
Fix Yandex.Disk authentication

Locales:
Update Japanese locale | thanks to shirayuki

UI:
Allow tab size configuration

General:
Fix GM.setClipboard
Fix GM_deleteValue
Replace experimental GM_addScript by GM_addElement support to workaround page CSP issues
Add .co.za to .tld list

UI:
Show incognito mode warning at script installation and import pages as well
Add script update item to editor file menu
'Darker' theme update

Firefox:
Make GM_cookie/GM_xhr always use the source tab's cookie store ID
Fix GM_info.isIncognito by showing a per tab value
Fix GM_download of blob objectURLs

Locales:
Update Vietnamese locale | thanks to IoeCmcomc
Update Ukrainian locale | thanks to toplinden

General:
Add ESLint rule id to error messages
Experimental GM_addScript support to workaround page CSP issues
Update ESLint
Allow to derive custom linter config from eslint:recommended
GM_xhr.onloadend support
Fix GM_xhr.overrideMimeType of anonymous requests
Fix GM.getTab and GM.getTabs
GM_xhr: Fix protocol-relative URLs
GM_xhr: Fix reported status of requests in progress
Add robustness to sandbox creation
Allow plain scripts to be imported via file import as well

UI:
Add script version to tab description
Fix WebDAV credentials being used for import and export
Accept more WebDAV server URLs formats
Improve action menu layout when warnings or hints are shown
Fix several editor search issues
Speed up script search

Sync:
Change backup file name to avoid character issues with some WebDAV servers
Fix an issue that some remote source code changes were not applied correctly

Locales:
Update Serbian locale | thanks to zoranzoki21
Update Japanese locale | thanks to shirayuki
Update Chinese (traditional) locale | thanks to austin-chang
Update Italian locale | thanks to bovirus
Update Indonesian locale | thanks to Azhe403

Firefox:
Fix file export when download mode is set to 'disabled'
Make badge icon text color configurable

General:
Add GM_info.isFirstPartyIsolation
Allow scripts to be recognized more easily at the developer tools
Internal cleanup and speedup
Fix an issue that user *cludes caused script update confirmation dialogs

UI:
'Darker' theme update
Fix an action menu issue when GM_registerMenuCommand is executed
Allow scripts to be removed via editor menu

Firefox:
Fix GM_notification.onclick being called too often
Improve incognito tab handling
Avoid 'normal' mode cookies being sent via GM_xhr from incognito tabs
Fix an issue with very long view-source: URLs
Action menu scrollbar fixes
Fix mobile view

Locales:
Update Chinese (traditional) locale | thanks to austin-chang
Update Portuguese-Brazil locale | thanks to igorruckert

Firefox:
Fix sometimes empty action menu
Fix crash in FF < 58 if WebDAV, Dropbox or Yandex.Disk sync is enabled

Locales:
Update Portuguese-Brazil locale | thanks to igorruckert

Firefox:
Relax minimum Firefox version to 52
Fix some action menu scrollbar issues
Improve storage cleanup
UI:
Dark theme including OS support
Scroll tab view content instead of page
Fix version number based sorting
Check for unsaved changes before tab close/reload | thanks to narcolepticinsomniac
Add an option to enable/disable scripts at their settings tab
Always show 'Search' and 'Add new script' action menu items
General:
Add .co.nz to .tld
Update FileSaver.js
Allow more GM_xhr headers to be modified
Make GM_xhr.finalUrl available on progress events as well
Fix GM_openInTab.close when the tab is currently moved
Internal improvements, cleanup and speedup
Fix sometimes not working second level domain check
Implement GM_notification silent option
Fix GM_notification onclose listener
Make GM_notification user interaction mandatory if possible
Sync:
Yandex.Disk support
Add script synchronization using OneDrive
Add a button to revoke Google Drive access tokens
Use refresh tokens for less Google Drive re-authorization requests
Note: you need to revoke existing access tokens at the utilities tab to make use of this
Locales:
Added Belarusian locale | thanks to bogachenko
Update Turkish locale | thanks to Tmp341
Update Russian and Ukrainian locale | thanks to bogachenko
Update Italian locale | thanks to bovirus
Update Japanese locale | thanks to shirayuki
Update Chinese (traditional) locale | thanks to hsuan1117
Update Vietnamese locale | thanks to vigov5
Update Indonesian locale | thanks to ReksaTresna

Firefox:
Require unlimitedStorage permission (-> FF >= 56!)
Fix tab creation with parent ID at Android (Dashboard, GM_openInTab, ...)

Sync:
Fix cloud services authentication

Locales:
Update Russian and Ukrainian locale | thanks to bogachenko
Update Portuguese-Brazil locale | thanks to igorruckert
Update Italian locale | thanks to bovirus

General:
Allow multiple @webRequest tags
Sandbox fixes
Support SHA-256 subresource integrity hashes independently of the browser's crypto API
Better userstyles.org userscript support
Fix a memory leak when using GM_xmlhttpRequest which could lead to crashes
Allow repeated space at some script header tags (author, namespace, copyright)
Speed up @include regexps by optimizing .*.*
Compress zip archives again

UI:
Remember script storage export setting
Show menu commands below the userscript entry at the action menu
Don't show script updates if the user is active or a fullscreen window is present
Enable section save button on changes only

Locales:
Update Spanish locale | thanks to TBM13
Update Turkish locale | thanks to Tmp341
Update Russian locale | thanks to bogachenko
Update Indonesian locale | thanks to ReksaTresna
Add Dutch locale | thanks to The947thTokay
Update French locale | thanks to zek0faws
Update Indonesian locale | thanks to Azhe403
Update Chinese (traditional) locale | thanks to PeterDaveHello and cedarkuo
Update Japanese locale | thanks to shirayuki
Update Italian locale | thanks to bovirus
Update Spanish locale | thanks to rocammo
Update Hungarian locale | thanks to hubalazs

Sync:
Fix sync to TamperDAV
Improve WebDAV protocol compatibility for NextCloud support

Experimental:
GM_cookies support

General:
Fix script externals import issues
Fix import from zip files with folders
Use https for all links to tampermonkey.net
Fix GM_xhr.responseType 'document' support
Allow script editing via external editor by using TamperDAV
Reduce memory footprint (by doing less caching)
Add GitLab subgroup support
Add several .com.* 2nd level domains
Sync:
Increase WebDAV protocol compatibility
WebDAV based cross-browser sync (beta; tested with OwnCloud and TamperDAV)
UI:
Minor layout refresh
Fix blurry icons
Avoid action menu flicker on GM_registerMenuCommand usage
Update dark theme | thanks to narcolepticinsomniac
Add narcolepticinsomniac's dark theme matching editor layout
Make the script filter bar work if its visibility is enforced via Custom CSS

General:
Allow ESLint inline configuration again to make globals definition work
Import and export of external resources (@resource and @require)
Replace zip.js by JSZip
Fix an internal cache related problem which could have caused data-loss
UI:
Invert (and fix) meaning of the case-insensitivity search option
Further search bar improvements
Allow the editor button bar to be restored via Custom CSS
Set ESLint ECMAScript version according to the browser's capabilities
Locales:
Update Portuguese-Brazil locale | thanks to igorruckert
Update Japanese locale | thanks to ScratchBuild
Update Italian locale | thanks to bovirus
Update Chinese (simplified) locale | thanks to efreedev

General:
Switch from JSHint to ESLint 4.19.0
Clean GM_tabs data on tab close
Fix script externals update
Locales:
Add Croatian and Serbian locale | thanks to faultyfuse
Update Italian locale | thanks to bovirus
Add Hindi locale
Update Russian locale | thanks to Dr-Yukon
Update Turkish locale | thanks to ali-demirtas
Update Portuguese-Brazil locale | thanks to igorruckert
UI:
Lint in background for more editor responsiveness
Limit displayed script name length
Update CodeMirror to version 5.35
Rework editor search
Add action menu option to exclude a script from a domain
Remember scroll position on tab switch
Firefox:
Create a new beta channel
Make Instant Injection more reliable
Sync:
Dropbox based cross-browser sync (beta)

UI:
Add a lot of editor commands to the menu

General:
Add .co.th to .tld

Locales:
Update French locale | thanks to zek0faws

UI:
Fix script update setting saving
Fix display of SVG icons
Better @downloadURL none support
Minor script install page fix
Allow script source code to be searched as well
Editor menu
Fixes related to the modified script close icon
Fix script storage editor to not reset to its initial data on every tab selection

General:
Fix an issue which could break page scripts
Avoid update requests to Greasyfork scripts with a pinned version
Fix GM_notification click listener
Fix GM_download progress events
Fix GM_download.abort
Fix issues if GM_openInTab.name= or GM_openInTab.close was used at more than one tab

Locales:
Add Vietnamese | thanks to Connor37
Update Russian locale | thanks to BychekRU and irainman
Update Italian locale | thanks to bovirus
Update Norwegian locale | thanks to LarsSimonsen
Update Czech locale | thanks to engycz
Update Indonesian locale | thanks to DhannyNara
Update Arabic locale | thanks to Alayady
Update Russian locale | thanks to BychekRU

Simple script storage editor
Allow all browsers to use synchronization
Allow script update servers to signal unchanged content
Fix blank action menu issue
Make GM_download support all common details properties at FF >= 52
Experimental: Enable browser sync at FF >= 53
Add GitLab and Bitbucket support
Avoid some 'Unchecked lastError' warnings | thanks to tophf
Add Portuguese locale | thanks to Sara F.
Update Polish locale | thanks to hawkeye116477
Fix issues at some pages
Make sure all config is written before reloading
Fix issues at nightly builds
Add an option to add custom CSS to the Tampermonkey UI
Add an option to disable the update check on a script base
Allow scripts to run at XML pages | thanks to Thom1729 for the slight lead
Fix some sandbox functions (set/clearTimeout/Interval and add/removeEventListener) to properly handle unusual arguments

Use "stickering" to improve the icon visibility at dark themes
Log @require related errors at the page console
Fix some rare internal exceptions
Update Korean locale | thanks to KENNYSOFT
Fix CSP related issues
Add ZenBurn editor theme
Visual bookmark support

Add Korean locale | thanks to KENNYSOFT
Fix GM_notification
Enable webRequest support at Firefox 52+ to fix many GM_xhr related issues (finalUrl, cookies, ...)
Fix missing action menu icon at internal tabs
Make xhr response headers available at readyState 2 and higher
Add time and browser to backup names
Fix relative URL handling
Fix sync issues of script comment properties
Fix doubled include/exclude editor dialogs
Make * include file URIs as well
Update the ES6 script template

Speed up storage writing
Fix extension reload for version 51 and above
Improved script search/filtering at the dashboard

Allow backup and restore with cloud storages (Google Drive, Dropbox, OneDrive)
Update Chinese (traditional) locale | thanks to TobySkarting
Update Czech locale | thanks to d3jv
Remove autodetection of some compatibility options
Update JSHint to 2.9.2

Fix the sandbox on{event} properties
Fix the editor replace code and show which part of the script text is going to be replaced
Update Chinese (simplified) locale | thanks to lychichem
Update saveAs to 1.3.2
Firefox: fix GM_download
Firefox: fix drag and drop script positioning

Fix cancelation of GM_xhr requests (not completely working in fetch mode)
Use a fallback in case the page CSP wasn't relaxed (disabled setting or cached page)
Update Portuguese-Brazil locale | thanks to oliveirafabio
Firefox: make the manifest Firefox 47 compatible