AMQP-294 Remove Class and Package Tangles

Move Consumer Channel Registry methods to new class to avoid
a class tangle between RabbitResourceHolder and ConnectionFactoryUtils.

Move exception translation to a new support class to avoid package
tangle between connection and support.
Merge pull request #87 from garyrussell/AMQP-294

* garyrussell-AMQP-294:
  AMQP-294 Remove Class and Package Tangles