isnmtoken(), istoken():  Fix to ensure the regex has to match the 	entire attribute value.
isnmtoken(), istoken():  Fix to ensure the regex has to match the
	entire attribute value.

Add ability to save list of "empty" elements to a file -- enabled by
constant in the code.

sk-/python2.7-type-annotator,sk-/python2.7-type-annotator,sk-/python2.7-type-annotator