#24 Pipeline idlePause mis-used in threads

[Todd Pierzina]

idlePause is ms to pause when Map or Target has processing to do, but its input queue is empty. This happens when, e.g., the target gets ahead of the source/map. Once the thread concludes that it should rest, it sleeps idlePause milliseconds. This is correct.

However, at the end of every iteration, the thread ALSO pauses for this interval. It should NOT do this. It may still be desirable to put a pause in here, though, if there are resource deadlock issues or something. So we just need the pipeline to have Yet Another Pause attribute--iterationPause, say--and the loop should sleep for that amount instead of the idlePause.

[Brian Shin]

added DEFAULT_ITERATION_PAUSE=0 in MigrationPipeline

[Todd Pierzina]

Code adjusted to pause only at beginning of each iteration. Added iterationPause as a separate property as described in the details.