Made echo client print help message.

If the jid and password are not supplied, the options list will be
displayed instead of hanging trying to connect to a nonexistant server.
Added __repr__ for JIDs.
Merge branch 'develop' of github.com:fritzy/SleekXMPP into roster
Add rename_node method to disco plugin.
Add rename_node method to disco plugin.
Merge branch 'develop' of github.com:fritzy/SleekXMPP into roster
XEP-0030 bug fixes.
Adding stream tests for XEP-0030.

Fixed some errors when responding to disco requests.
Fixed typo
Added option for iq.send to accept a callhandler.

The callback will be a stream level handler, and will not
execute in its own thread. If you must have a thread, have the
callback function raise a custom event, which can be processed
by another event handler, which may run in an individual thread,
like so:

def handle_reply(self, iq):
    self.event('custom_event', iq)

def do_long_operation_in_thread(self, iq):
    ...

self.add_event_handler('custom_event', self.do_long_operation_in_thread)

...take out already prepared iq stanza...
iq.send(callback=self.handle_reply)
Actually make the Iq callbacks work for real.
Fix several errors in SleekTest.

Notably, not sending an expected stanza will not silently pass.
Add support for using xml:lang values.

Support is only for adding literal XML content
to stanzas. Full support for things like multiple
message bodies with different xml:lang values is
still in the works.
Fix xml:lang tostring test.
First pass at a new XEP-0030 plugin.

Now with dynamic node handling goodness.

Some things are not quite working yet, in particular:
    set_items
    set_info
    set_identities
    set_features

And still need more unit tests to round things out.
Merge branch 'develop' into roster

Conflicts:
	sleekxmpp/basexmpp.py
Update some docs.
The documentation effort continues.

Also, need to start working on a replacement for the XEP-30 page in the
wiki since the API has changed significantly.
And some more docs.
Implement a few more static node handlers.