[Fluxus] commits: midi incremental messages

[gabor papp]

hi all,

i added support for incremental midi cc messages. you can set the 
encoding mode using (midi-set-cc-mode). three modes are supported 
'absolute, 'ableton and 'doepfer. the first one is the default, the last 
two ones use different incremental encodings. 'ableton sends a signed 
7-bit value, while 'doepfer sends 1 or -1. the setting should match the 
encoding mode of your midi device. if everything is done right, 
(midi-cc) should send signed incremental values.

best,
gabor