Move to Maven 3

We want to move to use Maven 3 for our builds. Maven 3 is far more reliable and properly handles dependencies. Plus, many of the plugins actually work, so I think that our assemblies will get easier (e.g., actually reusing the dependency information rather than duplicating the dependencies in the assembly descriptors). However, I think that last point means that there will be some impact and required changes to our POM files and assembly descriptors that will prevent our build from also being usable under Maven 2.