This fixes a few more issues that went unnoticed for years.

the "nothing is as good as creating a release to finally find a bug" release

this fixes a problem with PSGResume that went unnoticed for years.

the (now mature) PSGlib 1.2

Differences from v1.0:

• no more clashing between noise and third wave channels when one is allocated to music and the other to SFX
• PSG file conversion works both with VGM and VGZ files
• PSGSetMusicVolumeAttenuation added, to handle music volume (can be used to fade-in and fade-out)
• PSGSilenceChannels and PSGRestoreVolumes added, useful if you need to stop processing audio

From now one, expect any changes ;)

(and I also added PSGSFXCancelLoop function to sets the currently looping SFX to no more loops)

PSGFrame and PSGSFXFrame calls are now separated, thus making it possible to switch ROM banks between background music and SFX processing.