Yay switches now

Previously, switching the composition before stopping it broke the State Assumptions. Now, applpi knows which to stop independent of trying new channels. Yay. Toggling the play button also changes its text from 'play' to 'stop'.

Renamed getCurComp to currChan. This reflects move to enum messaging about the radio buttons. Somewhat wasteful allocation for the Composition array to suit it though. Oh well.

Pulled repeated spinner adjustment calculation into adjSpinner().

*next* Anticipate trying other layouts. Perhaps flow again?
Flowlayout now

Flowlayout looks better than the grid layout because the radio buttons don't need to be as wide as the jspinnner. Good enough that I'll merge to master. Or at least up to radios. Will reopen layout to try javaFX sometime later.
Packaged for use

Jarred up this project so I don't have to run it from the console.
:x
-m missed these