Create connection for each qpid notification.

Previously the qpid notifier created a connection to the qpid broker
when the notifier was initialized and reused that for each notification.
This is broken when API workers are used.  Instead, just create a new
connection on demand when a notification gets sent out.

Fix bug 1100317.

Change-Id: I7a17e5e4bd8efd771ff8cd0e1d04107a79789763
Use oslo-config-2013.1b3

The cfg API is now available via the oslo-config library, so switch to
it and remove the copied-and-pasted version.

Add the 2013.1b3 tarball to tools/pip-requires - this will be changed
to 'oslo-config>=2013.1' when oslo-config is published to pypi. This
will happen in time for grizzly final.

Remove the 'deps = pep8==1.3.3' from tox.ini as it means all the other
deps get installed with easy_install which can't install oslo-config
from the URL.

Retain dummy cfg.py file until keystoneclient middleware has been
updated (I18c450174277c8e2d15ed93879da6cd92074c27a).

Change-Id: I4815aeb8a9341a31a250e920157f15ee15cfc5bc
Merge "Create connection for each qpid notification."
Merge "Use oslo-config-2013.1b3"