Add runtime configs for loading in ram and voice stealing

[paulfd]

Still needs some testing; allows for hint_ opcodes to control ram loading and voice stealing.

[jpcima]

Are hint opcodes handled at global level, or can it be also per region (sample) ?

[paulfd]

For sforzando apparently they're in a <control> block, but I did not test anything.

I guess they could be anywhere. You're thinking of possibly tagging individual samples to load in ram?

For the voice stealing it's a bit touchy, since the algorithm choice is rather from the killed voice than the killing one...

[paulfd]

Now disables/enables the power follower depending on the stealing algorithm.