First stage of options rework.

- Split Configuration into RCConfiguration and SessionConfiguration;
the first for options which are saved to .rc files and the second
for options which are saved in a session file.

- Move some options from the old `master' Configuration object into
SessionConfiguration; this needs more refinement.

- Reflect many RCConfiguration options in an expanded Edit->Preferences
dialog; my intention is to remove the corresponding menu items
eventually.



git-svn-id: svn://localhost/ardour2/branches/3.0@5075 d708f5d6-7413-0410-9779-e7cbd77b26cf

gtk2_ardour/ghostregion.h

@@ -23,7 +23,6 @@
 #include <vector>
 #include <sigc++/signal.h>
 #include <libgnomecanvasmm.h>
-#include "ardour/configuration.h"
 #include "canvas.h"
 
 namespace Gnome {