Ion tail simulation for RKF drift lines
Added an option to simulate the signal due to the ion tail. The method used corresponds to the "detailed ion tail" model in classic Garfield, http://garfield.web.cern.ch/garfield/help/garfield_130.html#Ref1018
Added an option to simulate the signal due to the ion tail. The method used corresponds to the "detailed ion tail" model in classic Garfield, http://garfield.web.cern.ch/garfield/help/garfield_130.html#Ref1018