Add calculation of the Hodoscope offset time and ADC Starttime

1) Modified THcHodoscope to calculated fOffsetTime which is
the average fo the difference between the ADC pulse time and
the TDC time for all good hits with both PMTs ends hit.
This allows a correction for bad raw ADC reference times
in the other detectors.

2) Added calculation of fADCStartTime which is calculated the
same as the fStartTime but uses the ADC TOF corrected pulse time.