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...
as of now compound systems (Genesis and Arcade) are translated to
separate chips.
this improves audio quality and makes things easier.
it also allows you to change the volume of each chip on a Genesis.
also adds SegaPCM system with 16 channels!
