This commit introduces support for HAL rendering and making it the default rendering option. The configuration now registers an additional MappingJackson2HttpMessageConverter with the according HAL modules registered and makes this the default JSON renderer if the default media type is configured to HAL (which it is by default). To change this, set RepositoryRestConfiguration.setDefaultMediaType(…) back to application/json.
Refactored the PersistentEntityJackson2Module to turn the PersistentEntityResource into it's correct shape (turning associations into links) and the delegate to the default rendering, so that the HAL customizations provided by Spring HATEOAS can kick in. Adapted test cases to the change in default representation format.
Upgraded to Jackson 2.3.0, Spring 3.2.6 and Spring HATEOAS 0.9.0.BUILD-SNAPSHOT. Upgraded to Gradle 1.10.
Additional changes include:
* Re-wrote the monolithic Controller into separate controller classes that have a more narrow focus.
* Implemented common functionality as a `HandlerMethodArgumentResolver` rather than as a helper method in a controller class.
* Re-implemented JSONP functionality as an HttpMessageConverter rather than inline within a controller class.
* Updated to Jackson 2 for all JSON handling.
* By relying on spring-data-commons, spring-data-rest now handles all supported Repository types: JPA, MongoDB, and GemFire.
Added support for MongoDB and GemFire repositories by relying on spring-data-commons to provide the metadata rather than maintaining internal metadata information that is store-specific.
Replaced Spock spec tests with JMock unit and integration tests. Started integrating Jetty 8 into the testing so MVC testing can be done against a live server.
