IPA client and server tool set used authconfig acutil module to
for client DNS operations. This is not optimal DNS interface for
several reasons:
- does not provide native Python object oriented interface
  but but rather C-like interface based on functions and
  structures which is not easy to use and extend
- acutil is not meant to be used by third parties besides
  authconfig and thus can break without notice

Replace the acutil with python-dns package which has a feature rich
interface for dealing with all different aspects of DNS including
DNSSEC. The main target of this patch is to replace all uses of
acutil DNS library with a use python-dns. In most cases, even
though the larger parts of the code are changed, the actual
functionality is changed only in the following cases:
- redundant DNS checks were removed from verify_fqdn function
  in installutils to make the whole DNS check simpler and
  less error-prone. Logging was improves for the remaining
  checks
- improved logging for ipa-client-install DNS discovery

https://fedorahosted.org/freeipa/ticket/2730
https://fedorahosted.org/freeipa/ticket/1837

This has been completely abandoned since ipa v1 and is not built by default.
Instead of carrying dead weight, let's remove it for now.

Fixes: https://fedorahosted.org/freeipa/ticket/761

The new framework uses default.conf instead of ipa.conf. This is useful
also because Apache uses a configuration file named ipa.conf.

This wipes out the last vestiges of the old ipa.conf from v1.

We used to install it as ipa, now installing it as ipapython. The rpm
is still ipa-python.