Merge pull request #150 from Catrobat/11.08_UndoRedoProgressDialog_v3

11.08 undo redo progress dialog v3
Implementation: @schmidiM [ms], @dladenhauf [dl]
Acceptance: @galstc05 [sg]
Merge branch 'master' into 11.07_scrolling_view
Added hack to prevent app from crashing when drawing, pinching and scrolling