Added Changes RE: indexing relations, marshalling elastic search output and paginating results. Added Restful controller.
Merge branch 'develop' of github.com:MetadataRegistry/ModelCataloguePlugin into develop

Conflicts:
	ModelCatalogueCorePlugin/test/integration/uk/co/mc/core/SearchISpec.groovy
added bad search request. Fixed index on extension belongsTo. Fixed url mapper.