DATACMNS-353 - Make Spring HATEOAS purely optional.

Extracted the implementation of UriComponentsContributor from PageableHandlerMethoArgumentResolver and SortHandlerMethodArgumentResolver into dedicated subclasses so that we can really make Spring HATEOAS an optional dependency.

The integration tests are now guarded with an assumption to run on Spring 3.2 as Spring 3.1 has issues with JavaConfig and configuration method overrides. We've upgraded to Spring Data Build 1.2 snapshots so that the tests can be run with -Pspring32. This effectively means that the Spring Data Web support can only be used with a current Spring 3.2. Added a note on that in the reference docs and JavaDoc of @EnableSpringDataWebSupport.

Original pull request: #39.