minor improvements
remove duplicate code
Merge branch 'ide' of gh:Catrobat/Catty into ide

* 'ide' of gh:Catrobat/Catty:
  exclude not editable bricks (in progress)
  bug fixes brick transition back to script view (#157 #117)
  hide navigation bar and toolbar, fixes (#157 #117)
  zoom brick when selected (#157 #117)
  added base transition (#157 #117)