Removed unreferenced string resources
Removed unused landing page and strings related
Removed unused code for tracking and related strings
Removed more code and string about unused location tracking
Removed unused code for ownCloud extensions and strings related
Improved messages
Replace 'ownCloud' with reference to app_name
Updated translations without unused string resources
Removed unused drawable resources
Removed unused layout resources
Removed unused menu a preference resources, and related code
Removed languages not mantained, including Chinese from Bulgary; really
Updated Chinese translation after fixing bug in version string
Merge branch 'develop' into clean_up
Merge branch 'develop' into clean_up
Merge pull request #292 from owncloud/clean_up

Clean up: removed unused resources (specially strings and drawables)