Convert pathoGen to multi-process

Change-Id: I9de5c59ff2180d7f59a4a153f4aa64e531a23d21
PathoGen: Add stats of how many promotions of each size

Record how many set()s of each size each worker has performed. Print
this at the end of the run.

Change-Id: I914c6650884a20de21cfb80feb1f3818c638c947
Revert "PathoGen: Add stats of how many promotions of each size"

This reverts commit 03cdac96e76d07d7d6b2cf82c1e31b0bc5747c2b.

Conflicts:
	perfrunner/workloads/pathoGen.py

Change-Id: I84c72a42946694c33dc64719e9b2fec04b269fa5
PathoGen: Rework how we detect the end of the iteration...

... and stagger which worker input queue documents are initially
dispatcher from. This ensures that a particular worker (and crucially
it's memcached front-end thread) performs set()s of all the different
sizes.

Change-Id: Ica7d5a810dbca4e1202330626864287a2cd434d1
TEST: cProfile support

Change-Id: I72fde75e0aa755067aced398bab1f195de529a47
DJR TEMP: Hacks needed for running on port 12000

Change-Id: I29db18076853c8af232d8c54eb2d28d761adcf70
DEBUG: Remove sleep; change num workers to 17

Change-Id: I75d18000886704c2b0a1e639ec4c2eedef323487
DEBUG: 10k documents

Change-Id: If280b90e5dc114b3fa8cb3aae602b2f734ac682b
WIP: Change to 100k docs, 21 workers, 20 iterations

Change-Id: Ifeedaa427ea375b8256d9fc27c8acc623d676f2d