Added configuration of max limit of stored notifications on preferences
screen
Added new notification types "documentFile", "sharedFile", "enrollment"
and "enrollmentRequest". Changed notifications icon.
Updated translation
Updated icons for notifications
Added module for offline QR code generation. The generated QR code
encodes the user ID.
Updated the regular expression for nickname validation. Added "@"
character at the beginning and adjusted the max length of the nickname.
Fixed NullPointerException exception on QR code decoding.
Merge branch 'develop' of git@github.com:Amab/SWADroid.git into develop