caolan/async — pull request #338 by tautologistics (2013-06-24 21:15:26+00:00)
Title: Simple pause/resume for queues

Since there are no pause/resume methods on queue, I was setting concurrency to 0 to pause and setting concurrency to n (where n > 0) and then calling process() in order to resume the queue.

To avoid having to remember to call process() each time, I moved the concurrency property to _concurrency and made concurrency a getter/setter that calls process() if concurrency increases.