Merge pull request #30 from He-Ro/master

Updated German translation (again)
Official release 2.3.5.7
Swap the consent/decline buttons (to be consistent with Android UI guideline)
Use Holo blue light instead of black as background color for many buttons (except for task control ones)
Add missing string resource `pref_summary_get_packages_from_dropbox` using Google translate
Remove more unused resources
Added Playstore description
Added German translation of Playstore description