Update vhost defines to support ipv6only

See here: c0b36ae2e93bb9e1f04209bf260d2ac67e0ef088

The commit above tried to add an ipv6only option.  I don't know why, but
the defines were left out of the change.  This brings the remaining
defined resources inline with the commit above.
Merge pull request #36 from puppetlabs-operations/ipv6only

Update vhost defines to support ipv6only