improve performance to retrieve all groups of a user

git-svn-id: https://svn.apache.org/repos/asf/archiva/redback/redback-core/trunk@1428612 13f79535-47bb-0310-9956-ffa450edef68
remove commented code
caching will be in LdapRbacManager.

git-svn-id: https://svn.apache.org/repos/asf/archiva/redback/redback-core/trunk@1428613 13f79535-47bb-0310-9956-ffa450edef68
caches not needed

git-svn-id: https://svn.apache.org/repos/asf/archiva/redback/redback-core/trunk@1428614 13f79535-47bb-0310-9956-ffa450edef68