added events tab
fixed crash when all sources were unsubscribed
manually stitched together events in KIP with corresponding sample building object
improved building detail vc to show upcoming events
improved building detail vc, added associated events and news, added mensa info
show nearest bus stop in building detail vc (dummy)
added table header view, added flags in news source model
mensa list section headers
added remote refresh callback in delegate
added keywords to maps search
Merge branch 'Maps' into develop
Merge branch 'News' into develop

Conflicts:
	uni-hd/news.xcdatamodeld/news.xcdatamodel/contents
corrected maps tab
Merge branch 'Mensa' into develop
fixed crash with building without campusRegion
Building Data ergänzt (Theoretisches Institut, Physikalisches Institut etc.)
Merge remote-tracking branch 'origin/Maps' into Maps
Merge branch 'Maps' of github.com:Uni-Heidelberg/Uni-HD-App into Maps
BuildingNumbers ergänzt.
Merge branch 'Maps' of github.com:Uni-Heidelberg/Uni-HD-App into Maps