Sources of max-useful differ between calculations of comm.eff. and ser.eff.

[kingshuk00]

This is with respect to the current distributed version, not the version at github.

In file simplemetrics.py:

• The source of max-useful while calculating the load balance and communication efficiency is raw_data['useful_max'][trace]
• The source of max-useful while calculating the serialisation efficiency is float(raw_data['outsidempi_dim'][trace]

Is this intentional? These two quantities do not match in case the trace has a disabled region.