extra's for pvr.demo add-on

This adds more dummy data to the PVR Demo add-on in order to make things a bit easier for skin developers without a PVR setup. It is based on this package by Jezz_X: http://forum.xbmc.org/showthread.php?tid=142639

I made the following changes to it:

- Added dummy recordings
- Corrected the paths to be compatible with current XBMC
- Replaced the channel streams to a Big Buck Bunny stream.
- Removed any reference to real tv + radio stations / programmes for legal concerns
- added generic channel logos
- Added more of the available genre colours in the EPG
- Added genre colors documentation file
- Some other minor things