[RELEASE] 3.1.1 hotfix

[RELEASE] Merge BETA into MASTER

[NEW] Refactor attachments

Update strings.xml

Translated changed logout message and title

[FIX][IMPROVEMENT] CAS button not showing and CAS button style

[IMPROVEMENT] Image compression

[NEW] Add message action menu item to copy permalink from tapped message

[NEW] Provides support for http basic authentication

[IMPROVEMENT] Add dialog confirmation for logout 

[FIX] Reactions counter not showing

flexboxlayout dependency

[CHORE] Fixes spelling in README.md: beeing -> being