core : User Name modified on user login

When a user logs into the User Portal or Admin Portal the
user name is modified and it looses the domain name attached
to it.

This patch appends the domain name to the user name before updating
the user info in database with the info from Ldap.

Change-Id: I072f9aa8dc706533682b53d8b5a56e9b2dc09b82
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=892631
Signed-off-by: Ravi Nori <rnori@redhat.com>