break up arguments for stereo_panning and duty_cycle_pattern
note_type fade is signed
properly document arguments for vibrato, tempo, pitch_slide etc

change audio channel numbers from 0-7 back to 1-8
change all note macros back to single note macro
todo: fix comments with old macro names, update noise macros/instrument names

same as previous, but for songs instead of sound effects

rename functions, clean up address/wram comments, other misc
only broken up so that all changes are viewable on github