Sync with oslo incubator

Sync with oslo incubator at 45890dae35cd14a25175cdce7c12a5f9acbd712f

Change-Id: I44ecc69f1d952061be7cb2f41678b879ded93eae
Sync oslo-incubator.middleware module

This syncing has contained oslo-incubator.middleware module
to get capability of x-openstack-request-id.

Change-Id: I8e3b7d23bc1def705a0399bbd5015241a0fba8b1
Partial-Bug: #1324065
Support x-openstack-request-id for Heat

This patch aims to support "x-openstack-request-id" for Heat.

Nova, Cinder and Neutron have realized "x-openstack-request-id" functionality
by using oslo-incubator.middleware. This functionality will enable effective
log tracing between Heat and Heat caller.

Change-Id: Ida2f3d33b02557c2117aade27ccac7d9351886c9
Closes-bug: #1324065
Merge "Sync with oslo incubator"
Merge "Sync oslo-incubator.middleware module"
Merge "Support x-openstack-request-id for Heat"