pithos: remove dependency from synnefo.lib.queue.Receipt
incorporate AMQPClient instead of synnefo.lib.queue methods for sending queue messages
Fix code formatting to conform to the PEP 8 style guide
Include instance in queue messages.
Different queue message types use different keys.
Remove lib package.
Merge commit 'v0.9.0' into packaging
Conflicts: pithos/__init__.py pithos/api/management/commands/__init__.py pithos/backends/lib/rabbitmq/__init__.py pithos/backends/lib/rabbitmq/queue.py pithos/lib/user.py pithos/middleware/user.py pithos/settings.py...