Merge branch 'release/0.3' into develop
Roll up to 0.4.
Quit button.
Add some easily triggered loops.
Horizontal group triggering!
Merge branch 'feature/group-trigger' into develop
Define syntax for the looper.
Column loop selection and playback.

Todo:
- specify to wrap at the first blank or play the entire column.
- let the panic kill the thread
Reformat the markdown.
Tweak the in-column audio kill.
Roll on 0.4!
Merge branch 'release/0.4'