De-cruft maven poms

[jjg-123]

There are a lot of redundant dependencies in the poms. Much of this is because some older versions of maven (back to 2.x) needed to have explicit references. This makes them much harder to read and understand. Also, there were a bunch of tests scattered throughout the code, but some time ago these were centralized into a couple of explicit testing modules. There are still references to test-jars all over the place that need to go away. Pare them back to the minimum each.