Awood/checkstyle

A Checkstyle Buildr plugin that reads its configuration from `.checkstyle`.  The .checkstyle file is what the Eclipse Checkstyle plugin uses and is now the canonical source for configuration options.

Additionally:
* Update Checkstyle to latest version
* Add ability to use the SuppressWarnings annotation to turn off Checkstyle for specific items
* Adjust import ordering file slightly to reflect the current state of the project
* Add `checkstyle:xml` and `checkstyle:html` tasks so we can create Checkstyle reports if desired.