IDM-05: Link or unlink an identity from another organization

Executive Summary: 
A community member wants to link his/her identity in another organization to his/her community identity so he/she can use either identity when logging in to a community website or application. (Or, the user may wish to unlink an identity from another organization so it can no longer be used to login.)
User Importance Summary: 
Access to resources and services in the public research computing community requires persistent identities for individuals. Individual users need to be able to authenticate (prove their identity) to the system, and it is helpful if they can use an existing identity (e.g., their campus login).
Target Communities and Sizes: 
Community members at InCommon and eduGAIN institutions - 1,000 < N < 10,000