XvMC: revert [25318] and do it in a better way. Remove some warnings because of forgotten inclusions.

This can cause needless I/O, and consistutes a trivial local privilege esclation.

If you packaged without staged installation you're going to have a problem (but packaging without staged installation is to utterly lame in the first place)

Qt4 - Input Manager: cleanup, fix behaviour of enableVideo(), initialize variable that can be used and renaming.

- nice images
- fix playlist status bug
- timeslider not updated bug
- button/slider position and detection of button click is hardcoded

update the release documentation, only supported signatures are v3 signatures (gpg 2.x generates v3 sigs by default, but not gpg 1.x)