[FTS] measure performance with maxPartitionsPerPIndex set to 64 (default now is 32)

The current default value of maxPartitionsPerPIndex is 32. That always seemed kind of low to me, but when we last tried a higher value, performance got slower. Steve Yen and Chiyoung had discussed it and theorized that more pindexes was allowing forestdb to keep the disk busier.

Now that we have added moss, we tend to be committing larger batches to disk. It's possible that with moss we can achieve better performance with a higher setting.

Will Gardella I'm assigning this to you. I was thinking it was something we could have Sandip try, but will let you set his tasks/priorities.