Java Refactor of betamax-core

Removing the dependency of Groovy from betamax-core.

Some of the classes are nasty due to the Groovy -> Java migration, but all of the tests are passing, and I tried really hard to only convert one class at a time.

I only removed deprecated tests, and did not change any tests to make them valid.

The only breaking functionality is the the removal of support for Groovy properties. If this functionality remains necessary, we should add support for it in a separate module, like a Groovy module.