kdetv snapshot including v4l2 plugin

Hello List,

I've uploaded a snapshot that contains an enabled v4l2 plugin. It should work 
equally well as the v4l1 plugin when your system supports the XV display 
method.

The v4l2 plugin:
- only supports XV video display method because it's the only one that works 
without any limitation
- supports snapshots
- supports all controls a driver exports (Video->Video hardware controls)
- should work on more hardware

The drawback of exporting all hardware control functionality is that channel 
files are now "bound" to a specific plugin/hardware combination. If you use 
the same file on multiple devices, expect problems. Example: If I use the 
channel file created by the v4l2 plugin for a XVIDEO device, the picture 
settings are messed up and I don't see an image.

TODO before the next release:
- Add a warning if a channel file is loaded for another device than the one it 
was created with or change the channel file naming scheme (?)
- Doc update für v4l2 plugin
- Many kdDebug() -> kdWarning() conversions - it's a mess all over the program
- Pray to get feedback from a few people whether the plugin works *hint*


Have a lot of fun,
Dirk