When OutOfBrokers, retry with previously-disconnected brokers.

This is a partial workaround for #15. Really, broker management should
be completely rearchitected, but today is not the day for that.
Yell about un-thought-about config values.
Add a bit more logging to client creation/closing
More verbose logging on failure
Fixed tests
Fixed tests
Add logging to metadata refreshes
Small tweaks
Merge pull request #61 from Shopify/metadata_request_logging

Add logging to metadata refreshes
Log the other two sites where disconnectBroker is called
Merge pull request #62 from Shopify/more_logging

Log the other two sites where disconnectBroker is called
More informative logging around DecodingError, and bumped max msg size
DecodingError.Packet wasn't very useful
Merge pull request #63 from Shopify/verbose_decoding_error

More informative logging around DecodingError, and bumped max msg size