This kdestroy runs as root and wipes root's own ccachs ...
this is totally inappropriate.
Use a file ccache that ends up in the private tmp, so that if the
service is restarted the file is automatically removed.

https://fedorahosted.org/freeipa/ticket/6673

Signed-off-by: Simo Sorce <simo@redhat.com>
Reviewed-By: Martin Babinsky <mbabinsk@redhat.com>
Reviewed-By: Martin Basti <mbasti@redhat.com>
Reviewed-By: Christian Heimes <cheimes@redhat.com>

v2:
- use redhat_services.redhat_system_units.copy
- don't use wildcard imports
- add some empty lines to make pep8 happy

v3:
- make parse_ipa_version static

v4:
- make more methods static

v5:
- fix pylint issues
- use syntax that doesn't break with python3

v6:
- remove IPA_GETKEYTAB from paths, it's the same across distros

Reviewed-By: Stanislav Laznicka <slaznick@redhat.com>
Reviewed-By: Christian Heimes <cheimes@redhat.com>