2011-10-23 [colin] 3.7.10cvs44

	* src/addressadd.c
	* src/addressbook.c
	* src/addressbook_foldersel.c
	* src/editgroup.c
	* src/foldersel.c
	* src/folderview.c
	* src/grouplistdialog.c
	* src/prefs_common.c
	* src/prefs_common.h
	* src/summaryview.c
	* src/gtk/gtkcmclist.c
	* src/gtk/gtkcmclist.h
	* src/gtk/gtkcmctree.c
	* src/gtk/gtkcmctree.h
	* src/gtk/gtksctree.c
		Refactor some tree stuff (lots of code duplication there)
		and switch to cairo for tree rendering.