New variables have been added (undefined by default):
  krb5_dns_canonicalize_hostname
  krb5_pkinit_anchors
  krb5_pkinit_pool

These are set according to the ipa version requirements. See
roles/ipaclient/tasks/install.yml

For ipa versions prior to 4.5 it is needed to use ipa-client-install script
as a source for functions. But the script contains a global finally clause
in which the generated ccache file gets removed. Threfore the script is
temporarily copied to ipa_client_install.py and the global finally clause
gets removed from the copy. All this is done in a temporary directory, which
gets removed right after the import has been done.

For ipa versions prior to 4.5 it is needed to use ipa-client-install script
as a source for functions. But the script contains a global finally clause
in which the generated ccache file gets removed. Threfore the script is
temporarily copied to ipa_client_install.py and the global finally clause
gets removed from the copy. All this is done in a temporary directory, which
gets removed right after the import has been done.

A Object called options is generated as ipa-client-install and also
ipaclient/install/client.py functions are using this object.

inspect.argspec is used on configure_krb5_conf to find out if the function
requires configure_sssd as an optional argument or in the options object.

freeipa 4.4 is the first version that supports all needed functions.
Therefore a check has been added to make sure that ipadiscovery fails for
versions before 4.4.

The python bindings of ipa versions before 4.6 are having a different
structure.

ipa_python_version is the version gathered from ipapython.version.NUM_VERSION.
For ipa versions before 3.2.1, the version is generated from
ipapython.version.VERSION because NUM_VERSION changed the format two times
before 3.2.1.

The discovery was not working if a server has been specified. The domain has
been needed additionally. The domain is now gathered from the server name if
it is missing in this case.

- Backup ipa default conf
- Backup krb5.conf

This is needed to be able to use defined and undefined checks.

The sssd role has been deactivated in favor of the new sssd module, because the module is able to adapt an existing configuration.

The advantage of the use of SSSDConfig is that an existing configuration could be changed and not simply overwritten.

New documentation for incoming and outgoing arguments. Copied check from
library/ipaclient.py to do conflict checks if the check argument is set.

Documentation for domain, principal, keytab, ca_cert_file and kinit_attempts
has been added.

ca_certs_file has been renamed to ca_cert_file as it is used in
ipa-client-install.

The module is doing the important part of the code in ipa-client-install
to be able to use ipa-join on the client. get_ca_certs* from client.py are
used as a temporary solution.

IPA client imports are needed for discovery