[vdr] VDR-1.3.24: OSD speedup

Hi,

the attached patch speeds up OSD display a little bit.

I think it's wrong to tell cStatus that for example 2700 channel entries will be displayed when actually only 16 entries fit on screen.

The other sections speed up paging beyond the first respectively last item (similarly to single line scrolling).

Further ideas to reduce CPU load while scrolling: - Flush OSD after each scroll: will slow down scrolling and therefore most likely reduce CPU load. - Snoop ahead remote commands and do N scrolls at once, skipping N-1 paint operations. - Paint line by line and abort as soon as further remote commands arrive, to start over again.

Bye.