General Changes:
* Overhauled UI
* User script header format now requires inline comments only - no block comments
* Snippet headers now handle "@exclude" and "@run-at" tags

In Options Page:
* Simplified snippet multi-selection behavior
* Added exact-match snippet search filter
* Changes to "sync" and "enabled" now auto-save
* Included file input/export to options (supporting buttons and drag & drop)