[vdr] Patch to use Skip keys (Next + Previous)

[Klaus Schmidinger]

Peter Juszack wrote:
> Hallo
> 
>    Since a long time I wondered when the very common skip keys are 
> available in VDR.
> I believe these keys are available but unused on most remote controls.
> The attached patch adds to new keys kNext and kPrevious to keys.h and 
> keys.c.
> The patch modifies vdr.c and menu.c to switch channel up/down whith the 
> new keys.

I don't really see the reason why there should be yet another pair
of keys for switching channels up/down - there is already kChanUp/kChanDn.
Wouldn't it make more sense to use kPrev/kNext for jumping between channel
groups?

> I also modified the mp3 and dvd plugins to use the new keys. I can 
> provide patches therefor
> if the patch will be intergrated in VDR.
> 
> As logical mp3 jumps between tracks.
> 
> When playing a DVD Next and Previous have the same meaning like 4 and 6 
> and jump
> between DVD chapters. That is the common behaviour of stand-alone DVD 
> players.
> Very smart when replaying music DVDs because the different songs  are 
> DVD chapters.
> 
> I can also imagine to use Prev/Next to navigate between cutting marks in 
> a recording. (not yet implemented)

I've added that.

Klaus