* Makefile_tests.am:
	* tests/test_document_load_and_save.cc: Load a file and save it,
	then check the saved file against the DTD.
	* tests/test_document_load_and_save_all.sh: Run that test on all
	example files.
	* glom/glom_document.dtd: data_layout_notebook: Mention trans_set,
	so that this test succeeds.