Improve zonemgr validator and normalizer

The validator has been improved to support better both SOA format
(e-mail address in a domain name format, without '@') and standard
e-mail format. Allow '\.' character in a SOA format encoding the
standard '.' in the local-part of an e-mail. Normalization code
has been moved to one common function.

https://fedorahosted.org/freeipa/ticket/2053

ipalib/plugins/dns.py

@@ -27,7 +27,7 @@ from ipalib import Command
 from ipalib import Flag, Bool, Int, List, Str, StrEnum
 from ipalib.plugins.baseldap import *
 from ipalib import _, ngettext
-from ipalib.util import validate_zonemgr, validate_hostname
+from ipalib.util import validate_zonemgr, normalize_zonemgr, validate_hostname
 from ipapython import dnsclient
 from ipapython.ipautil import valid_ip
 from ldap import explode_dn
@@ -152,13 +152,6 @@ def _rname_validator(ugettext, zonemgr):
         return unicode(e)
     return None
 
-# normalizer for admin email
-def _rname_normalizer(value):
-    value = value.replace('@', '.')
-    if not value.endswith('.'):
-        value += '.'
-    return value
-
 def _create_zone_serial(**kwargs):
     """Generate serial number for zones."""
     return int('%s01' % time.strftime('%Y%d%m'))
@@ -678,7 +671,7 @@ class dnszone(LDAPObject):
             label=_('Administrator e-mail address'),
             doc=_('Administrator e-mail address'),
             default_from=lambda idnsname: 'root.%s' % idnsname,
-            normalizer=_rname_normalizer,
+            normalizer=normalize_zonemgr,
         ),
         Int('idnssoaserial?',
             cli_name='serial',