Release 14!

Release 14!

This release adds rate limits and failure (gen_server timeout) tolerance to the
AMQP codepaths, so that they always stay under their supervisor's restart
intensity.

This upgrade/downgrade path is a little racey:
  - It's not guaranteed that rate_limit is loaded before other modules.
  - The supervisors are running while the worker modules with shiny new init/1
    arguments are loaded.
This can cause full failure if something needs to restart while the upgrade is
ongoing.  Since these are just init codepaths, I'll take my chances.  It's like
the big sky theory, in the time domain.