only depend on webkitwidgets if we compile against qt5
fixed avatar handling if 2 notifcations are shown at the same time
added some cleanups to update dialog
fixed unused variable warning in user settings for linux
added missing globalsettings header file
updated icons
reworked update flow

~ disabled update for linux
~ use main networkmanager with caching
~ removed uneeded filedownloader
added inno setup configuration
debian packaging updates
added app mutex for installer on windows