* gladeui/glade-command.c: Fixed property commands to not unify across separate groups,
	and also to unify when they are not lists.

	* plugins/gtk+/glade-gtk.c, plugins/gtk+/gtk+.xml.in, plugins/gtk+/glade-model-data.c:
	  - Data properties now have DnD working
	  - Adding TreeViewColumn support
	  - Fixing liststore support to work for treestore


svn path=/trunk/; revision=1977