Sync latest from oslo-incubator

Changes include:
1523f00 threadgroup: don't log GreenletExit
a99c5f1 Report: Support Sequences and Mappings as Data
4ca5091 Fixes nits in module policy
411ba35 Simplify is_user_context method
5d43644 cliutils restore python3 string decode
a3220c5 add list_opts to all modules with configuration options
df774ff Import PublishErrorsHandler from oslo.messaging
d0a1fde Switch fileutils to use python logging
b2d35ee Use list.pop(0) to keep the code simpler
262fc82 Correct default rule name for policy.Enforcer
046bc2a Mask secrets when output conf

Removed fixtures that are no longer in oslo-incubator as the
previous reviews in this series switched to using the equivalent
fixtures in oslo libraries.

Cleaned up openstack-common.conf to include only the modules
that are still in oslo-incubator.

Change-Id: Ifd2d5bd506aeb2a9400c5075c3ca24b3c02d1cb6
Merge "Sync latest from oslo-incubator"