[vdr] Patch to avoid file system buffer trashing

[Carsten Koch]

Ralf Müller wrote:
> The day before I tried to find out if somebody ever had implemented 
> something to prevent vdr to trash the file system buffers. I did this 
> because I hate to wait 20 seconds for vdr to re-read my recordings 
> list. 

I tried your patch today and watched the available memory (using top)
when replaying. The number stayed the same. Excellent!

However, when I did FF or FR, the number decreased.
Ralf, can you reproduce the problem?
I am using plain vanilla VDR 1.3.30 with a few small patches
(SourceCaps, DeleteResume, burn) and of course your patch.

Carsten.