Title: #406: IPA: sanitize name in override search filter
@sumit-bose, code-wise the patch looks okay and I'll manually test the patch later
One things that worries me a little bit here is that we've been bitten by not
sanitized names before a few times. So, I'm wondering here whether the other filter
calls have been checked already or we should file a bug for that (as I don't think it
should be solved as part of this PR).
See the full comment at https://github.com/SSSD/sssd/pull/406#issuecomment-336841219