Various dependency clean-ups

Attempts to make the POM files a more accurate representation of what each module is actually using, and to standardise on placing versions in the root POM *only* (in the `dependencyManagement` section)

Testing: full unit test run; started Brooklyn and deployed MySQL+Tomcat cluster to localhost
camp-server was previously in an external repository, and ended up with its own set of preferred versions that did not match brooklyn. Unifying camp-server into Brooklyn has meant that some version numbers need to change so that the entire project has consistent versions of dependencies. In this case it's caused camp-server to depend on a newer version of Jackson. It's possible that this might introduce a bug but moving forward minor versions is generally safe and I have run all units tests and a smoke test with a real app. TBH I didn't mean to commit this comment, it's mostly a pointer for me for testing, and I will probably remove it when rebasing.