misc:runstat/profit: separate order statistics into an independent class

Separate order statistics from runstat as OrderRegress class to keep runstat
as clear as possible.

Signed-off-by: Zhengwang Ruan <ruan.zhengwang@gmail.com>
misc:runstat/profit: rename busProfit to busWin

1, The old busProfit only works to calculate the max/min business win, so rename
   it to busWin to match its real role.
2, Update other affected symbols accordingly because of #1.

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