Added get_uid_from_email.
Added get_uid_from_email.

inveniosoftware/invenio-accounts,inspirehep/invenio-accounts,inspirehep/invenio-accounts,tiborsimko/invenio-accounts,tiborsimko/invenio-accounts,tiborsimko/invenio-accounts,inspirehep/invenio-accounts,inveniosoftware/invenio-accounts,inveniosoftware/invenio-accounts