Fixed StackOverflowError in ControllerEntityLinks by delegating to the proper methods now. Clarified contract in EntityLinks interface. Added further unit tests to make sure the implementation behaves like the interface specifies.
Fixes#43.
EntityLinks allow accessing LinkBuilders or even Link instance based on components exposing REST resources for a particular domain type. The core implementation is ControllerEntityLinks that assumes a particular URI structure so that it can derive the URIs to be asked for per domain type. The domain type managed will be inspected from the @ExposesResourceFor annotation on a controller class. We provide a factory bean to allow configuring instances of ControllerEntityLinks based on a mapping annotation and LinkBuilderFactory.
Added infrastructure to activate automatic discovery of EntityLinks implementations through @EnableEntityLinks. This will automatically register ControllerEntityLinks instances for Spring MVC controllers annotated with @ExposesResourceFor as well as JAX-RS resources if JAX-RS is on the classpath. The mechanism essentially registers a DelegatingEntityLinks instance leveraging the Spring Plugin PluginRegistry mechanism to delegate to the actual EntityLinks instance actually registered for the entity type. It will become the primary EntityLinks bean in the ApplicationContext so that they can be autowired into client components safely.
