Janky Sequencer Version 2

I'd been playing around with writing songs and noticed that when I play a really long note, the playback would pause for a bit. To reduce this, I've implemented a note generation buffer, so that each note is generated one beat ahead of time - so when it's time to play the note it just reads it in directly. There is still some lag for particularly long notes (could be delays in the reading in of the note from the buffer) but to my ear it is improved.

I've also identified some glitches around importing in of synthesizer parameters from CSV. These are relatively minor but ideally I'll try to fix these somewhere down the line.