SAX-ext proposals, first set

[David Brownell <david-b@pacbell.net>]

As I promised a while back, I'm sending by some proposals
to address issues with SAX.  These would be in the "new
features" category; so they're not things to worry about being
in with "SAX 2.0.1" bugfixes.  Backwards compatible, all!

I'm about to send the first set of proposals, focussing on things
the XML Infoset identifies, but which SAX2 doesn't yet expose
even with the other "extensions".

Its's likely worth having consistent answers to these meta-issues,
at least if you like stylistic integrity in APIs:

* Meta-1:  Naming convention for extended versions of
  current interfaces.  I used a numeric suffix; easy to apply
  everywhere.  Does some other convention work better?

* Meta-2:  Implementation classes.  New ones, or extend
  the ones in org.xml.sax.helpers.* ... that's as optional as
  the org.xml.sax.ext.* stuff, but there's been no coupling yet.
  I proposed new classes (no coupling), but might prefer
  the simpler approach.

Apologies for the crosspost; I'll see responses sent to both
lists (or directly :) so adjust followups appropriately (that is,
please avoid followups to both lists).

- Dave