Updated logo

Update app to new backend URLs

* Add save button (can be disabled in Settings)
* Refine icons, buttons

* Fix searched fields for assignment
* Don't forget changes in running description

* Providers: Trello, JIRA, Google Calendar, any page
* Add running tracking duration
* Fix changing icon when time-tracking is started
* Prevent XSS attacks in assignment
* Chrome: fix authenticating in incognito mode
* Chrome/Firefox extension