zmq: switch back to not using message envelopes

In oslo-incubator, we default to not serializing messages using a
message envelope:

  def _cast(.., envelope=False, ...)

except using the v2 notifyer which explicitly passes envelope=True.

However, in oslo.messaging, we accidentally switched to using a
message envelope:

     def _send(self, ..., envelope=True):

This was not intentional and may be disruptive to users.

This issue was identified because the envelope=True path just doesn't
work! We don't have any zmq tests in oslo.messaging, but even in
oslo-incubator the code path isn't tested and has been broken since
I73aad7697cf83ad4aabb3c2058b7cc4f53f783c2

Partial-Bug: #1301132
Change-Id: I6aa2e2ac3cebf443719d64ebcd9eaadc0a9328b8
Bump hacking to 0.9.x series

In order to keep this patch to just a requirements bump, ignore new and
stricter hacking rules that are being triggered. Fixing up the code and
turning these on is out of scope of this patch and is for future patches.

Change-Id: I5711e066da1076486d291bc4f45359ecb26e1b1a
Add transport reconnection retries

When a rpc client try to make a RPC call and the server is unreachable
The rpc call hang until the server come back.

In most case this is the desired behavior.

But sometimes, we can prefer that the library raise an exception after a
certain number of retries.

For example in ceilometer, when publishing a
storage.objects.incoming.bytes sample from the Swift middleware to an
AMQP topic, you might not want to block the Swift client if the AMQP broker
is unavailable - instead, you might have a queueing policy whereby
if a single reconection attempt fails we queue the sample in memory and
try again when another sample is to be published.

This patch is the oslo.messaging part that allow this.

Closes bug #1282639
Co-Authored-By: Ala Rezmerita <ala.rezmerita@cloudwatt.com>

Change-Id: I32086d0abf141c368343bf225d4b021da496c020
rabbit/qpid: remove the args/kwargs from ensure()

Having an *args list following the retry kwargs just screams:

  SyntaxError: non-keyword arg after keyword arg

but we don't actually pass any args to methods invoked via ensure() so
these are just unused and can be removed. If we did want them in future
we could just use functools.partial().

Change-Id: Idef12bbc94d39c84ee06ddd6d743f3d2f705a8d1
Merge "Bump hacking to 0.9.x series"
Merge "Add transport reconnection retries"
Merge "rabbit/qpid: remove the args/kwargs from ensure()"
Merge "zmq: switch back to not using message envelopes"