Allow midi-poly-player to be associated with specific midi devices. Also implement midi-device-keys which returns a sequence of midi device event keys. Fixes #143.
Allow midi-poly-player to be associated with specific midi devices. Also implement midi-device-keys which returns a sequence of midi device event keys. Fixes #143.

chunseoklee/overtone,la3lma/overtone,ethancrawford/overtone,craftybones/overtone,Widea/overtone,mcanthony/overtone,pje/overtone,brunchboy/overtone