don't ignore jar files
Added SQLCipher to the project
Workaround for gradle to add *.so files to the build
Don't crash if the contact_mail is not set, but log the event to crashlytics
Moved token request tasks to here, added simple callback interface, code cleared up
Moved the OAuthConnector into the Application class context
Changed SyncHelper to use OAuthConnector from Application class
Usage of contact email from OAuthConnector in Application class
Ported messages to OAuthConnector from Application class
Ported UserlistFragment to use the OAuthConnector from Application class
Refactored CoursesDocumentsFragment download functionality to use the OAuthConnector
Created AuthenticationContract for saving the auth infos to the app db
Database encryption through SQLCipher, added authentication route to RestIpProvider

added encryption transition method to DatabaseHandler, added
Authentication table to app database, refactored DatabaseHandler and
RestIpProvider to correctly use the SQLCipher provided classes and
methodes
Proxying the SharedPrefs calls for OAuth infos to new authentication RestIpProvider route
Simplified OAuth workflow through usage of OAuthConnector.OAuthCallbacks and OAuthConnector consumer
Removed unused code due to change of OAuth workflow in SignInActivity
Fixed crash when trying to send feedback via options menu
Changed production flavor min API to 10,  version bump
Merge branch 'db-encryption'