Fix the matching_work count, display the small miner work count for debug
 * MM version >= 401412 can give you correct small miner matching_work count

If your MM version is 401411. please ignore hte MW[x...] values, it is
meaningless on 401411 MM code.
The temperature can be < 0C.
Update the default DH_DEC value from 0.1% to 0.2%