Update (v1.2) to DLTPulseGenerator: A library for the simulation of lifetime spectra based on detector-output pulses

However, in this update v1.2, the DLTPulseGenerator library was modified to allow the simulation of lifetime spectra consisting of non-Gaussian distributed and linearly combined Instrument Response Functions (IRF), since a Gaussian shaped instrumental response of a lifetime spectroscopy setup more likely represents an approximation as it reflects the experimentally obtained results. Eventually, this provides an improved modeling of the experimental instrumental response and, finally, leads to a more realistic simulation of lifetime spectra.