Add more AMQP options & Improved consumer performance.

Publisher:
   1. Ability to delete and re-declare an exchange and queue - useful for setup threads.
   2. Persistent delivery option
   3. Durable exchange option
   4. Transactions
   5. Aggregate samples (mimics JMS Sampler so tests can be somewhat comparable.)

Consumer:  
   1. Aggregate samples.
   2. Prefetch count
   3. Cache Queuing Consumer in instance.