add/remove clients from the clients hash

The actors hash is an auto-generated aggregation of users and clients.
It should not be used to make changes to users or clients hashes.

When adding clients use the clients hash from the existing_group.
When removing clients they should be removed from the clients hash.
Merge pull request #10 from jeremiahsnapp/jhs/fix_group_add_remove_client

add/remove clients from the clients hash