timing.exe: add timing from the largest peak

At this moment, timing.exe is considering both the "beast peak" (as defined in p348reco.h) and the list of all peaks. The best peak, by default, is obtained from

int peak_Best(const int method, const double master) const

where method is by default kPeak_BestTiming. That means that, in case cal. constants are off and the timing.exe code is used, the beast peak may be not the correct one to take into account. This may happen, since timing.exe is typically used to determine or update the time calibration constants

I suggest to add to the code also the analysis of the peak with the maximum amplitude, independently from the time.