RAR-Adapter

Hi everyone,

this is my first pull request, so please let me know if I didn't follow some important rule.

We've created this branch of the hazelcast master branch to fix some issues we had on WLS and WAS application servers:
* Deployment fails due to missing hashCode / equals on WLS and Jboss (#37, #182)
* "Transaction already active" exception on WAS/WLS (#83)
* Async transaction completion via other thread on WAS (might occur on WLS also)
* A very first idea of an XA implementation which has the heap storage in mind: Whatever is in the heap should not throw any exception during commit. This might not be true for elastic memory but is a starting point (as we use heap storage only)
As my knowledge about hazelcast's internals is quite limited, this XA implementation is not ready for production and should be considered as a technical demo - I'm happy about any input from hazelcast's internal transaction management.
* Replaced deprecated Hazelcast instance access through the new one
** Updated the documentation to reflect this change
* Added unittests based on standalaone ironjacamar (jboss RAR container)
* Added container specific deployment descriptors for WAS, WLS and Jboss (ironjacamar)

I'd like to continue to work on the RAR part as the the test coverage is still quite limited.
I'm happy to incorporate any feedback.

Kind regards,
Sebastian