ChannelManager - end of wip

* AudioOutput - toggleMute persist the current volume in _tmp var and restores on un-mute
* ChannelManager - mute/unmute a particular audioOutput
* jshint - added .jshintrc to src and test
* ChannelManager - assign, update, remove an AudioOutput, assign, update and remove frequencies to a ChannelBar in the patterns array
* tests - for ChannelManager basics (defined as global, assign AudioOutput Pattern)
* AudioOutput - added class as abstraction for jsSynth instance initialized  with a specific pattern
* Pattern - added class as abstraction for frequency values (channelBars)
* ChannelManager - added class for orchestration patterns andaudioOutputs
* TempoMat - changed the default noteResolution from 0 to 2 (quarter note)
* TempoMat - introduced *tempo:notetick* event to play the current note and left the *tempo:tick* event for painting purpose