Please review (cont.): Ticket #123 - whoami extended operation design and implementation

Design document:

http://directory.fedoraproject.org/wiki/Design/ldapwhoami

Ticket:

https://fedorahosted.org/389/ticket/123

https://fedorahosted.org/389/attachment/ticket/123/0001-Ticket-123-Enhanc...

https://fedorahosted.org/389/attachment/ticket/123/0002-Ticket-123-Enhanc...