Core + RPC: New method getAssignedResources.

- added method getAssignedResources(sess, member, service), the method returns all resources, where both the member and service are assigned.
- added method getAssignedRichResources(sess, member, service) with the similar function
- tests written
- RPC changed, so as it uses new methods
Merge pull request #187 from jirmauritz/getAssignedResources

Core + RPC: New method getAssignedResources.