DATAREST-217 - Significant overhaul of HTTP method support detection.

Refactored the way the general support for an HTTP method for the resource exported. The decision is implemented in RootResourceInformation (formerly RepositoryRestRequest). Removed request specific information from that class and introduced a HandlerMethodArgumentResolver to be able to inject HttpMethod instance into controller methods (filed https://jira.springsource.org/browse/SPR-11425 to get that support into Spring Framework itself).

Generally moved away from throwing NoSuchMethodExceptions and correctly expose HttpRequestMethodNotSupportedException instead to make sure Spring MVC renders the appropriate allowed methods if possible.

Removed RepositoryInvokerHandlerMethodArgumentResolver as a RepositoryInvoker can be obtained from the RootResourceInformation where necessary.

Related pull request: #125.
DATAREST-216 - Added integration test.

Forgot to commit integration test with 5dd33b.

Related pull request: #126.