[vdr] Duplicate channels list

Hi Klaus,

What is the motivation behind the logic of not allowing duplicate channels in channels.conf file?

I've tried to mimic channels settings of my Topfield receiver where I have favorite channels divided in different groups, while I can still access any channel on any satellite.

I've intended to have it that way: :News :Sport :Kids :Radio :@10000 All :Sat1 :Sat2 :Sat3

Where SatX group has all the channels of that satellite and News,Sport,Kids,Radio groups will act as favorite channels groups having the same channels as in SatX groups.

I had to change some functions in channels.c to update all duplicate channels when an update should be done.

If anyone is interested I'll post it here.