GRP-12: Use groups to control access within a resource

Executive Summary: 
A service provider needs to use groups to control access to his/her resource. The most common reason is to limit access to the resource to project groups that have active allocations via an official allocation process.
User Importance Summary: 
Community members need to be able to define arbitrary groups of people to which they can refer for authorization and communication purposes. Allocated researchers and service providers need to be able to use these groups on community resources.
Target Communities and Sizes: 
Service providers - 100 < N < 1,000