Channel groups faders are not checkable

Fixed doc clearing leaving sequences behind
MAJOR CHANGE: started to implement audio input support
Added PortAudio capture interface for OSX
Fix some OSX build issue
Fix MIDI feedback - moving a fader caused moving all non-zero faders.

Problem was that the code mixed MIDI and DMX data.
Tested only unix code; win and mac are copy&paste.
Merge pull request #143 from janosvitok/issue141

Fix issue 141: MIDI feedback - moving a fader caused moving all non-zero faders.