Allow 8 bit volume for YM2610 ADPCM-B
Remove sample mode macro in YM2610, it's always enabled and seperated channels.
TODO: ADPCM-B is still not implemented, FM Channel 2 is silenced in extended channel 3 configuration
this commit mostly rewrites the sample system.
as of now samples can be ADPCM, 8-bit, BRR or 16-bit
or something...
consider this VERY EXPERIMENTAL.
if you find any issues REPORT THEM immediately.
it's nearly 4am...
