reset rabbit connections before the vhost; stop queueconsumers before resetting connections

(avoiding bugs documented here https://groups.google.com/forum/#!topic/rabbitmq-users/lrl0tYd1L38)
Explicitly check that connections are closed by tests.

Includes the following fixes:
- kill the queue consumer after various tests
- remove defunct 'autoretry' decorator
- remove disingenuous rpc responder tests (testing kombu behaviour *and* patching incorrectly)
- raise an exception other than socket.timeout on proxy timeouts to avoid confusing connection.ensure
remove ChannelHandler.on_error
remove leftover debug
add comment explaining re-raise of socket.timeout as a different error
Use expanded link
Merge pull request #141 from onefinestay/rabbit-fixes

modify rabbit reset order; close more connections