[ardour-dev] latest CVS commit

[Paul Davis]

   * major changes to layering + xfades
   
	a) when regions are created or moved so that that they
            overlap, ardour now offers two different models
	    for how to layer them. The options editor
	    provides control between two models:

	       1) More recently moved or added regions are higher
	       2) regions with later starting positions on the timeline
	            are higher.


           For most people, model #1 will be preferable while
	   recording, overdubbing and importing. For many,
	   model #2 will be preferable when editing by moving
	   regions around (within or between tracks)

        b) two models provided for xfades created by overlapping
	   2 audio regions. they can either be "Full crossfades"
	   which span the entire overlap, or "Short crossfades"
	   which last 15ms and just provide a smooth transition
	   between the two regions.

	   
Work still to do:
    
    - unify the crossfade model to provide a single type that
       can be resized
    - turn off region fade in/out if that end of a region is
       part of an xfade
    - provide GUI ops to resize xfades

      libardour:  0.860.0
      ardour/gtk: 0.561.0