Added some of the REST API for the rating service. (Work in progress)
GET ratingdefinitions url=/api/rating/schemedefinitions
GET ratings url=/api/node/{store_type}/{store_id}/{id}/ratings
git-svn-id: https://svn.alfresco.com/repos/alfresco-enterprise/alfresco/HEAD/root@21068 c4b6b30b-aa2e-2d43-bbcb-ca4b014f7261