[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. 

Excellent work, Ralf!
I have 4 disks in my VDR system and 5 more VDR disks in my server,
most of them are in standby most of the time, so it takes even
longer here to bring up the recordings menu for the first time.
I'll try your patch next weekend.

Thanks,

Carsten.