Phoenix 180

First revision for review.  There are some open points here.  Still no test case added to consume the stats.  Will do the performance test once the system is available with me.
Also, we won't use targetConcurrency and maxConcurrency. Instead we'll add all guideposts for the regions here (they'll get pruned later when we apply/intersect them with the scan start/stop row). This will help in a bunch of ways by dividing the query up into smaller equal sized scans - we won't get lease expiration exceptions from the server b/c the client will be specifying smaller chunks. We'll also get better fairness between queries, b/c no one query will dominate a thread for too long a time. It also simplifies things quite a bit.