Do not manually redisplay file actions

Calling register() is enough, the file list is now automatically
notified of file actions changes.
Updated to use the updated FileActions API

This makes the music file actions works in other views like the sharing
overview.
fix the file actions for the public sharing page
fix the play state handling and click actions
Merge pull request #249 from owncloud/fileactions

Updated to use the updated FileActions API