Cleanup in preparation for full changeover to ndex-java

deactivated agent specs in api_spec.js
removed obsolete files for MemberInvitation, MemberRequest, admins
removed unneccessary schema initializations
commented out currently unused uploadAccountImage
temporarily restore init function for Agent.js - will be obsolete soon
NDEx-Site updated to use Request code in ndex-java

Depends on supporting code in ndex-java, in a parallel feature branch
Bug fix: undefined JIDs.