These are not game limitations, just restrictions for the macros to behave properly
same as previous, but for songs instead of sound effects
mostly so that sound effects that only use the noise channel are labelled 'Ch7' instead of 'Ch1'
except for wram.asm and sram.asm also delete unused yellow file
2→1 8→2 1f→3
rename functions, clean up address/wram comments, other misc only broken up so that all changes are viewable on github