-Automatically delete 0.00 CHF in add_new item so that it isn't necessary to delete the text before entering the value anymore.
-Show Number of participants in Activity main
-Show progressbar while loading contacts in choose_contact Activity
-Linked ProjectParticipants to Tagfilter Activity
-Fixed a vast number of Code Analysis warnings
-Removed Add Participant button.
-Merging Chrissies Stuff into GUI_upgrade