The current code flow precludes the use of the policy_path module
parameter that's documented. It's actually called policy_file in the
code.
What's worse is that the policy_file branch actually tries to open the
file named by the policy parameter, even though policy and policy_file
are marked as mutually-exclusive.
This change fixes the logic bug in policy_file and updates the
documentation to reference policy_file. The old parameter policy_path
is provided as an alias
eab9ca9a00