Title: #3615: Various pylint improvements
# Enable literal-comparison linter again
The literal comparison linter checks for "value is 0" or "value is
# Fix wrong use of identity operation
Strings should not be compared with the identity operation 'is' or 'is
# Add new env vars to pylint plugin
The vars api.env.host_princ and smb_princ where introduced a while ago.
Sometimes parallel linting complain about the attributes. Add both to
the list of known members in pylint_plugins.py.
To pull the PR as Git branch:
git remote add ghfreeipa https://github.com/freeipa/freeipa
git fetch ghfreeipa pull/3615/head:pr3615
git checkout pr3615