* created ArdourCanvas::CanvasFlag as a base class for flags
* removed obsolete cruft from midi_model
* made MidiTimeAxisView and MidiRegionView work together to display program changes as
names by means of MidiPatchManager
git-svn-id: svn://localhost/ardour2/branches/3.0@4307 d708f5d6-7413-0410-9779-e7cbd77b26cf