Description of problem:
Internal error and trace back when attempting to add a dns AAAA record with subnet prefix.


<snip>
 ipa dnsrecord-add --aaaa-rec=fe80::5054:ff:fe2c:918f/64
Zone name: testrelm
Record name: dhcp-100-19-80
ipa: ERROR: non-public: ValueError: IPAddress() does not support netmasks or subnet prefixes! See documentation for details.
Traceback (most recent call last):
  File "/usr/lib/python2.6/site-packages/ipalib/backend.py", line 125, in execute
    result = self.Command[_name](*args, **options)
  File "/usr/lib/python2.6/site-packages/ipalib/frontend.py", line 420, in __call__
    self.validate(**params)
  File "/usr/lib/python2.6/site-packages/ipalib/frontend.py", line 686, in validate
    param.validate(value, self.env.context)
  File "/usr/lib/python2.6/site-packages/ipalib/parameters.py", line 740, in validate
    self._validate_scalar(v, i)
  File "/usr/lib/python2.6/site-packages/ipalib/parameters.py", line 1427, in _validate_scalar
    error = rule(ugettext, value)
  File "/usr/lib/python2.6/site-packages/ipalib/plugins/dns.py", line 115, in _validate_ipaddr
    ip = netaddr.IPAddress(ipaddr)
  File "/usr/lib/python2.6/site-packages/netaddr/ip/__init__.py", line 289, in __init__
    % self.__class__.__name__)
ValueError: IPAddress() does not support netmasks or subnet prefixes! See documentation for details.
ipa: ERROR: an internal error has occurred
<snip>

Version-Release number of selected component (if applicable):
ipa-server-2.0.0-16.el6.x86_64

How reproducible:
always

Steps to Reproduce:
1. See description
2.
3.
  
Actual results:
internal error traceback

Expected results:
User friendly error message stating the issue and how to correctly define AAAA record.

Additional info:

There is nothing logged in the /var/log/httpd/error_log