Update dom4j from 1.6.1 to 2.0.0
dom4j is what's powering most of our XML representation. The library that we're using now (1.6.1) is quite old. I'd love to see it updated to the latest 2.0.0 release, for two reasons:
1.6.1 pulls in an old, incompatible Xerces parser, which I want to get rid of.
2.0.0 makes use of Java generics.
2.1.0 at this time with Java8+ support