This actually completes the aaa rewrite of 3.5.
Thanks to Ravi to have the courage to look into it.

As long estimated, the sync process of users and group from directory into the local engine database is not required.

Hence we can remove a large chunk of complex code which effects the product complexity and produce huge load on database and ldap server.

Dropping this within 3.5.1 will enable us to reduce support effort and avoid potential issues that have no actual value.

The merge is clean since the master aaa and the 3.5 aaa are the same, so no reason to keep this code around.