No border for message area (as in mockup)
Window geometry saved when window is resized
Splitter position saved when splitter is moved
Update de.ts

revised all of german translation.
fixed some original translation strings
adjusted translation messages

as discusses here: https://github.com/tux3/qTox/pull/848#discussion_r20851990
Italian translation: update
Core update
Group chat button at the bottom of contact list resized to 16x16 like other buttons
Fix some nullptr dereferences in Audio

Fixes #859
Italian translation: update
warn on can't read file, fixes #860
Attempt to fix #859
move new functions to a more logical location
Fixed restoring of window geometry when "Start in tray" is unchecked