Development marc

-> merge master into development_marc only said "already up to date", so I think this request is going to be merged without issues. 

- fixes x-acceleration test
- Fixes issue that activity indicator didn't stop loading in the most downloaded programs section as Ralph mentioned in my last pull request. Now this is solved.
- fixes app crash when object has no look
- fixes #171: TabBar Item now with Charts
- loading indicator hidden when download of a program is cancelled