Maven artifacts for the broker

Build on QPID-1916 hooks for Maven to enable broker, bdbstore and management-common Jar files being created as Maven artifacts. This simply involves adding them to the release.sh script and tweaking their respective build.xml files to enable Maven POM generation. Additionally OSGi MANIFEST generation is enabled for the broker, by adding a skeleton .bnd file.

The BDB store plugin has had the test application code moved to src/test to allow the perftest and systest dependencies to be removed, otherwise they would be included in the POM.