audio/engine.asm: Set pitch to 0 on rest notes.

Before this, there was no way to tell whether a rest was being played.
Check a note's pitch to see if it's a rest.
Clean up NoteNames and rewrite DrawChData.
Merge remote-tracking branch 'froggestspirit/master' into master

Brought the visualizer back to the main screen.

Didn't include the amplified volume read on channel 3.

Conflicts:
	misc/musicplayer.asm
Music Player: Don't reset visualizer state when switching modes.
Remove globals.asm from the repository.

This used to be a generated file, and was committed by mistake.
Music player: Start can back out of zen mode.
Merge pull request #3 from yenatch/fix-note-endings

Properly end notes in the visualizer.