misc:runstat: extend RunStat to use ProfitRegress flexibly

Extend RunStat to specify numInstruments argument so that ProfitRegress can
serve more instruments parallelly.

Signed-off-by: Zhengwang Ruan <ruan.zhengwang@gmail.com>
misc:runstat/profit: fix max/min profit were affected by updateProfitByOrder

The max/min profit were not correct because they were possibly updated new
values while updateProfitByOrder() updating order profit.

Signed-off-by: Zhengwang Ruan <ruan.zhengwang@gmail.com>