fix some lint Warnings

- remove duplicate icon (arrow)
- allowBackup for catroid - since default is true (and seemed to be
  working), set to true
- suppress warnings HandlerLeak; added TODO
- moved .png files for standard project into drawable-nodpi
- replaced "..." in dutch strings with ellipsis character
- remove unused icons for upload/copy/download notification
suppress warnings

with update to sdk 18 some methods are deprecated.
as a quickfix the warnings are suppressed with "deprecation"