Improve help strings

Follow oslo.config style guide for help strings better to create
consistent help strings:
* Capitalize first word of each help string
* Finish help strings with "."

Change-Id: Ia08fa09593661e6e5b834d98bbd92689c2674075
User a more accurate max_delay for reconnects

In an HA deployment, a 60 seconds delay between reconnects can be quite
problematic. This patch changes the delay calculation by setting the max
delay to 5s and by changing the way it is increased.

Unfortunately, this is one of the places where both our main drivers are
not consistent. Rabbit's driver uses configuration parameters for this
whereas qpid's driver has never had one. However, I would prefer not
adding configuration paremeters to qpid's driver for the following
reasons:

    1. Most of OpenStack services depend on the messaging layer, hence
    they need it to be available. A 5s delay seems to be reasonable and
    I could argue the need of tune it further. Although so frequent
    reconnects can add load to the network, that wouldn't be the main
    issue if one of the brokers go down.
    2. We're trying to move away from configuration options towards using
    transport URL. This path is still not clear and I would
    prefer avoiding adding new options until we clear it out.

Change-Id: I537015f452eb770acba41fdedfe221628f52a920
Closes-bug: #1281148
Pass the session to QpidMessage constructor

The patch in I6e37780cc28737cfd56b6719ec8d9cebbc9bb278 added a new class
for the QpidMessage which was wrongly initialized when processing a
message.

Change-Id: Iaf525fc6ee9e56100c89863f9c651f20c148ecb5
Closes-Bug: 1282038
Add a link to the docs from the README

Newcomers often struggle to find the docs for Oslo libraries. Let's
help them out a little.

Change-Id: I68cb214ad117ff1c45e83df302f37dba485147f6
Add log_handler to oslo.messaging

Move log_handler from oslo-incubator to oslo.messaging and include
unit tests. This patch also adds an additional test case from the
original version in oslo-incubator. Originally, the test case only
checked to make sure the notification was not sent. Now a positive test
case exists to test both paths.

bp graduate-notifier-log-handler
Co-Authored By: Ben Nemec <bnemec@redhat.com>

Change-Id: I9ea051ec7e3614579341a31d8dc1c13d9514b8a9
Merge "Improve help strings"
Merge "Add log_handler to oslo.messaging"
Merge "Add a link to the docs from the README"
Merge "User a more accurate max_delay for reconnects"
Convert to oslo.test

bp graduate-oslo-test

Change-Id: Iff1eebac011dab26468a7f1475b5c36b0bb2a7d2
Allow to requeue the notification message

This patch allow to requeue the notification received by the
notification listener.

Partial implements blueprint notification-subscriber-server

Change-Id: I49c4ba91224c280e479edb19289ccb337a2ab843
Add multiple exchange per listerner in fake driver

This patch allow the FakeListener to listen on multiple FakeExchange.

Partial implements blueprint notification-subscriber-server

Change-Id: I9830cc01efdd931f6628853f7e84b947d7b855c9
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.

This patch allow this.

Closes bug #1282639

Change-Id: I32086d0abf141c368343bf225d4b021da496c020
Allow missing data notification endpoint callback

Some information about the notification (ie: message_id and timestamp)
are currently not available for the application.

This change add them.

Change-Id: I83e562725205fb270f6065fe1118c3c9865b2294