- Stream::id(), Stream::lang()
- whitespace pings (but disable when using http poll)
- make stanza error conditions work for both 1.0 and old

- xmpp-im (messages, roster, subscriptions, presence, privacy)
- document xmpp-core
- provide complete support for xmpp-core.  this means all functionality from
  the draft, and noting behavior issues (like IQ semantics) in the
  library documentation.

- SASL "EXTERNAL" w/ client certificate
- SASL "ANONYMOUS" ?

credits:
  MD5 algorithm by Peter Deutsch (Aladdin Enterprises)