Preserve glade files when switching from libglade to gtkbuilder format

[Christian Persch <chpe gnome org>]

Hi;

recently more projects have been switching from libglade to gtkbuilder,
converting existing .glade files to .ui with gtk-builder-convert, and
then svn removing the .glade files from svn.

However, glade-3 is still not working on all features in the gtkbuilder
format (e.g. nautilus' and gnome-terminal's .ui files break badly when
edited with glade-3).

Please check that glade-3 can correctly edit and save your .ui files;
or else the .glade files should be kept in svn so that changes to the
UI may still be made (using glade-2 or glade-3 w/ glade format and then
converting again with gtk-builder-convert).

	Christian