Create Looper note manipulation modes

[derrickthomin]

Make a new screen where you can mess with an existing loop. Ideas:

• Give it a BPM and number of bars, and let it quantize what's in the loop.
• Use drum pads to do performance type things? Like change velocity while loop is playing, transpose up, etc.

[derrickthomin]

Added a "remove random note" function but plenty of other fun to be had with this