Merge pull request #12 from wilkinsona/maven-plugin

Enable easy installation into local Maven repo
Version upgrades

Upgrade the versions of numerous dependencies

The move to Spring 4 means that WebServceMessageDrivenBean no longer
compiles (Spring's support for EJB 2.1 MDBs was remove in 4.0). It
has been deleted _temporarily_.

New deprecation warnings caused by some of the version upgrades have
yet to be addressed.

XMLUnit cannot be upgraded. The four Axiom testDomPayload tests fail
with 1.2 or later due to it apparently being more sensitive to
attribute differences.