GRP-05: Invite members to a group

Executive Summary: 
A community member needs to invite one or more individuals (“invitees”) to become members of a group. The invitees will not become group members until they accept the invitation. The community member must have the administrator or manager role in the group.
User Importance Summary: 
Community members need to be able to define and manage arbitrary groups of people to which they can refer for authorization and communication purposes.
Target Communities and Sizes: 
Community members - 10,000 < N < 100,000