optionally print MESMER parameters to output file
add printouts of sum of weights and wnorm at end of generation
Skip nuclei and null-weight events in MuE
new interface to MESMER nuclear pair production (with current data format in MuE::MuEtree.h)
Added new parameter Emax_e in data format. Matched to MESMER v1.1.6
version 1.0.0 for FairMUonE