* doc/Doxyfile.in: Switch settings to generate the user
	documentation.
	* doc/Makefile.am (edit_user): Remove variable.
	(edit_devel): New variable.
	($(DOXYFILE_USER)): Generate it directly from
	$(srcdir)/$(DOXYFILE).in.
	($(DOXYFILE_DEVEL)): Adjust to use edit_devel.