Removed the loadProject while returning from Stage or reload the Stage

Concerning #301 

I removed the loadProject, which was called when return from Stage and when the Stage was reloaded, so this should work very fast now.

Jenkins Testrun:
http://catrobatgw.ist.tugraz.at:8080/job/Catroid-custom-branch-test/1003/
(The web tests fail, because the api was changed to https)

Btw. Critical Issue