add QueueThrottle.FetchedMessages and RestAfterEmptyCycle
let stoplight.sleep return immediately when TimeSpan.Zero
pass QueueThrottle to MessageFeed and utilize RestAfterEmptyCycle
fix remaining count
add more metrics for tracking queue volume
add QueueThrottle unit tests
restore MessageSubscriberTypeExtensionTests
change gauge to counter
remove counter that's already incremented
rename IQueueProcessor to IEnvelopeProcessor
introduce IQueuePartitionProcessor (QueuePrep)

simplifies some startup code in HubService
Merge pull request #37 from daptiv/refactor-queue-names

Refactor queue names
Merge pull request #36 from daptiv/easy-cpu-when-queues-are-empty

Easy cpu when queues are empty