Change to support x-openstack-request-id vs our own.

[Endre Karlson]

### Copied from https://bugs.launchpad.net/heat/+bug/1324065 ###

Nova, Cinder, Glance and Neutron already supported x-openstack-request-id.

  Nova: https://blueprints.launchpad.net/nova/+spec/cross-service-request-id
  Cinder: https://blueprints.launchpad.net/cinder/+spec/add-standard-req-id-header
  Glance: http://docs.openstack.org/developer/glance/glanceapi.html
  Neutron: https://bugs.launchpad.net/neutron/+bug/1239923

x-openstack-request-id is worthful functionality especially for the operator who's tracing problem's root cause.
It's also worthful functionality for Heat because Heat caller will be able to log heat's x-openstack-request-id.
This will enable effective tracing between Heat and Heat caller.

Nova, Cinder and Neutron have realized this functionality by using oslo-incubator.middleware.

My plan is:

  1) sync oslo-incubator with oslo.middleware
  2) modify to use request_id middleware in heat

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/99323

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/99323
Committed: https://git.openstack.org/cgit/stackforge/designate/commit/?id=bd145831692d13ba417dce4fb4e9b8f2c3cac117
Submitter: Jenkins
Branch: master

commit bd145831692d13ba417dce4fb4e9b8f2c3cac117
Author: Endre Karlson <email address hidden>
Date: Wed Jun 11 11:39:17 2014 +0200

    Sync in o.middleware and replace our own

    This syncs the above and removes our own code for the request-id.

    Bug: #1328840

    Change-Id: I00ac021be48439a14681f9090ba3a13113a60429