Updates the testing infrastructure to use the latest relesae of junit and
leverages the new extension mechanism to create an easy to use testing
framework. Also adds additional test coverage for several plugins.
Adds custom coroutines specifically for use within Actions. This
implements all features of the previous system, however, does not rely
on a separate executor to wake up continuations.
Note: since Actions are still ran by an executor and a small chance of
overlap exists the ActionCoroutine implementation uses atomic counters
and references.
Gary Tierney