Implemented xib for MensaSectionHeaderView
Merge branch 'Mensa' of https://github.com/Uni-Heidelberg/Uni-HD-App into Mensa

Conflicts:
	uni-hd.xcodeproj/project.pbxproj
removed overlay properties from maps model
fine tuned tab bar icons
fixed talk speaker url, added possibility to edit event entry in calendar, added 'show on map' button (all in talk detail view)
implemented building detail vc
Merge branch 'Maps' into develop

Conflicts:
	uni-hd/news.storyboard
Merge branch 'Mensa' into develop