Remove memory leaks of RepositoryRestMvcConfig

If you call getObject() directly on a FactoryBean it will create a memory leak because the bean is not managed by the application context.

Therefore I removed all calls to getObject() and let the context insert the dependency.

I tested this with my application using Tomcat 6 and jProfiler 6's Telemetry view. After a stop or undeploy the non-heap memory usage goes back down when running the GC.