increase pre-loaded file limits

[newlifedrama]

Since computers tend to have lots of memory these days, e.g. 4 Gbytes or more, it would be nice to be able to preload up to 50 sound tracks into memory (the limit now is 20). This will eliminate pretty much all disk accesses during the show. Perhaps also increase this and the max opened files limit to 100? And there's a limit of 6 minutes for playlist tracks that can be pre-loaded - perhaps make the limit a system option or something. I would be happy with 12-15 minutes for my current show.