Distribute unified-http-invoker.sar package for accessing JNDI, EJB2s and EJB3s over Unified HTTP invoker

In the same way that we've been provided the http-invoker.sar, AS should
now distribute the Unified invoker equivalent. Instructions on how to build
this can be found in:

http://wiki.jboss.org/wiki/EJBAndJNDIOverHTTPWithUnifiedInvoker

The way we should package this is up for debate. I'll start a design forum
thread when the time discuss this comes.

I'll attach a fully working unified-http-invoker.sar and example EJB that uses
it in a minute.

Any potential outcome of generating unified-http-invoker.sar for AS should
probably also include services needed for EJB3:

http://wiki.jboss.org/wiki/Accessing_EJB3s_over_HTTP_HTTPS