addded tab sorting of installed apps
fixed sortable all apps view
Merge branch 'develop' into feature/SortAppLists and implemented changing sorting direction

Conflicts:
	res/values/strings.xml
	src/de/otaris/zertapps/privacychecker/AllAppsActivity.java
	src/de/otaris/zertapps/privacychecker/AppController.java
	src/de/otaris/zertapps/privacychecker/AppListItemAdapter.java
	src/de/otaris/zertapps/privacychecker/InstalledAppsActivity.java
	src/de/otaris/zertapps/privacychecker/database/App.java
	src/de/otaris/zertapps/privacychecker/database/AppDataSource.java
fixed wrong sorting direction
added first version of category list
added onclick activity for category list items
ADDED arrows in tab names, reselection fixed
added fixed sorting to AllAppsActivity and refactored parts of it
fixed displaying all apps
previously only displayed installed apps, even in all apps view
Merge branch 'feature/SortAppLists' into feature/AppsByCategory

Conflicts:
	src/de/otaris/zertapps/privacychecker/AllAppsActivity.java
finished apps by category