Bug 12831: Local Only logins with LDAP

Bug 12831: Local Only logins with LDAP

Local only logins should continue to function when LDAP is enabled.
This was not the case after bug 8148 [LDAP Auth should FAIL when ldap
contains a NEW password].  For this case, we need to diferentiate
between local accounts and ldap accounts.  This is somewhat challenging
and thus this patch is only part of the story.

The other half can be achieved with bug 9165

Signed-off-by: Chris Cormack <chris@bigballofwax.co.nz>
Signed-off-by: Julian Maurice <julian.maurice@biblibre.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>