sync oslo-incubator for request_id shim

Sync 838a2a3 oslo-incubator to get the new request_id shim, so
can introduce a deprecation warning that tells operators upgrading
from Juno that their paste.ini files need to point to oslo.middleware

This also syncs all other modules, except policy, which looks like it
needs some changes to heat thus will be handled via another patch.

Note we shouldn't remove this request_id shim until after Kilo is
branched.

Change-Id: I35125ffa263b0522ff6dd0b80b0beb3cbc79999b
Related-Bug: #1380629
Merge "sync oslo-incubator for request_id shim"