Add generic IPTV backend
I would like to request a way to use an on-demand backend that makes it possible to use rtmpdump. There are a lot of channels that could be integrated into tvheadend this was, ie. http://live-tv-stream.googlecode.com/svn/trunk/LiveTV.xml
rtmpdump is GPL, so it could be integrated, but some generic way to simply execute an external command would probably be more flexible...