ipapython: port p11helper C code to Python

This replaces the binary _ipap11helper module with cffi-based Python code.

https://fedorahosted.org/freeipa/ticket/5596

Reviewed-By: Martin Basti <mbasti@redhat.com>

ipatests/pytest.ini

@@ -21,7 +21,6 @@ addopts = --doctest-modules
           --ignore=doc/examples/python-api.py
           --ignore=install/share/copy-schema-to-ca.py
           --ignore=install/share/wsgi.py
-          --ignore=ipapython/ipap11helper/setup.py
 markers =
     tier0: basic unit tests and critical functionality
     tier1: functional API tests

ipatests/test_ipapython/test_ipap11helper.py

@@ -17,7 +17,7 @@ import tempfile
 import pytest
 from ipaplatform.paths import paths
 
-import _ipap11helper
+from ipapython import p11helper as _ipap11helper
 
 pytestmark = pytest.mark.tier0