Use same mask pattern for reports as mask_password

The mask_password function in oslo.utils.strutils uses *** to replace
secret values. Use the same string here for consistency.

Change-Id: Icf6e2f8868845cd5eae59b9c976ebb11e385281d
Fixed a problem with neutron http policy check

When a rule "create_network": "http://127.0.0.1:8080/ or rule:default"
is configured in policy.json, create network with default values reports
a "Circular reference detected" exception.
The reason is, for unspecified values, default value of
neutron.api.v2.attributes.ATTR_NOT_SPECIFIED (that is, object())
is assigned by Neutron.
This creates a problem when jsonutils.dumps() is executed on a JSON
string that contains object(), thus reporting the said exception.
The fix replaces object() into empty value {} in the
dictionary, only for the policy check.

Change-Id: Ibd4859ed8c919ddb32cb75cc58c7f91d0e84a458
Closes-Bug: 1233707
Don't log missing policy.d as a warning

We default policy_dirs to look for a policy.d directory, but by
default that directory will not exist.  IMHO we should not be
logging a warning because of a perfectly normal default behavior.
INFO is plenty sufficient for tracking down any potential issues
with the policy dirs.

Change-Id: I183597f23b3a5eb44debd73f7a4a4444ca0d22fd
Merge "Use same mask pattern for reports as mask_password"
Merge "Fixed a problem with neutron http policy check"
Merge "Don't log missing policy.d as a warning"