* XEP-0060 (PubSub) extensions to Smack

*NB*: smackx-pubsub is now in IgniteRealtime's SVN repository, and is
actively maintained there:
http://www.igniterealtime.org/fisheye/browse/svn-org/smack/trunk/source/org/jivesoftware/smackx/pubsub

That should be considered the canonical source repository; I'm leaving
this here in case there's stuff that hasn't made it into SVN, and for
the notes on ejabberd compatibility below.

Original code by rcollier: http://www.igniterealtime.org/community/people/rcollier
Posted at http://www.igniterealtime.org/community/thread/38433

Modifications by Michael Bridgen <mikeb@lshift.net>, including
Mavenisation.

** Building

This is a straight-forward Maven build.  Except that it depends on
newer versions of the smack jars than I can find anywhere in a Maven
repo, so I have included them here, along with a script for installing
them.  There are plans to have an igniterealtime Maven repo:
http://www.igniterealtime.org/issues/browse/SMACK-265.  Until then
we'll have to make do.

Note that many of the tests fail with OpenFire, because the library
follows v1.12 of XEP-0060, while OpenFire implements v1.8.

Most tests fail with ejabberd, because of its idiosyncratic node
scheme (see
http://dev.esl.eu/blog/2008/06/27/differences-openfireejabberd-part-i/);
but this may be fixable to some extent, and I'm trying it.

$ sh install-libs.sh
$ mvn -DskipTests install

This makes a jar file in target/, and installs it to your local Maven
repo.

** Debugging

Use the system property smack.debugEnabled to tell smack to show the
XMPP debugger.  I've put it in NetBeans's Actions tab (Project
Properties).

** Using with ejabberd

The tests will run into ejabberd's registration timeout, giving a 500
Resource Constraint error.  To avoid this, you can put an global
option in ejabberd.cfg:

%% Allow fast regiatrations for testing
{registration_timeout, infinity}.

The 3.10 Smack release also has an error in the SASL implementation,
which results in a NullPointException.  This needs a patch, which I've
included in the JAR for the time being.

(thanks http://www.ejabberd.im/node/3003 and
        http://www.igniterealtime.org/community/thread/35976)

Most tests still fail with ejabberd; I've started making the tests use
ejabberd's /home/ node structure, which ought also to work with
OpenFire.