Sync rpc from oslo-incubator.

This patch includes fixes for:

 * kombu: Fix lack of reconnect when using mirrored queues
 * zmq: support rpc envelopes
 * zmq: Fix IPC direct topic routing.

Change-Id: I3e494d0c1b72ed19ab4f590c5d5496a9b202633c
Sync eventlet_backdoor from oslo-incubator.

This update includes:

 * Add function for listing native threads to eventlet backdoor

Change-Id: Iaeed27ff95962a870364a3043991bc5412f1fa63
Spelling: compatable=>compatible

Change-Id: I9c84f8654e4eb7ccf3631e8c9830f33d90396e08
Merge "Spelling: compatable=>compatible"
Merge "Sync rpc from oslo-incubator."
Merge "Sync eventlet_backdoor from oslo-incubator."
Merge remote-tracking branch 'm_src_repo/master' into build-temp