fixed CAT-531

added try/catch to location of possible exceptions

added default case to switch statement
Merge pull request #1083 from Catrobat/CAT-531

[CAT-531] NullPointerException: LookFragment.onActivityCreated
cat-531 #fixed
fixes double entries in MainMenuActivity's setting menu, caused by merge of CAT-1055
Merge pull request #1087 from Catrobat/fixCorruptMerge

fixes double entries in MainMenuActivity's setting menu
Merge branch 'master' into LiveWallpaper_Master