[XML-SIG] Location of feature names

[Martin v. Loewis]

To get at the symbolic name of a SAX2 reader feature or property (such
as feature_namespaces, which is symbolic for
http://xml.org/sax/features/namespaces), you currently have to import
them from xml.sax.handler. 

Is that the official place for these things, or should they be
available through xml.sax? I don't mind either way; however, if this
is not changed before 2.0b2 freeze date, I guess xml.sax.handler
effectively *becomes* the official place.

Of course, it will always be possible to use the full name of the
feature, regardless of any variable name that may be present.

Regards,
Martin