Improves:
 - Android app icon is now shown without white circle

Fixes:
 - Log messages for push notifications got increased with each trigger
   Removed the duplicate configuration.
 - Push notification processing improved to ensure, things are not
   running in parallel.

Release version 3.0.9

Bugfix:
 - Scanner for login card does not always proper work
 - Upgrade unified push libraries (FCM fallback)
 - Fix black screen after login

Fix blackscreen during login

See merge request !2

Release version 3.0.7

Features:
 - Sort classes
 - Refresh UI on resume of the app

Release version 3.0.6

Fixes:
 - Login card for teachers

Release version 3.0.5

Features:
 - New restriction to switch to teacher mode
 - Tooltips in settings menu