ResettableMock interface integrated with isolated unit tests

The impacted mock classes and their new reset method have a combination of isolation and integration unit testing. Integration unit test is quite focused and simple to ensure that the interface resolves by the Autowired annotation and the reset clears the mocks of the sent message. It confirms this and also confirms simple usage with the spring context wired together. Change relates to issue 64. https://github.com/skyscreamer/nevado/issues/64