bugfix: i was already in use, changed to j
removed obsolete for loop
removed blank lines
setting bin_width instead of numnber of bins, adapted config files
variable to store bin width
getting bin width
added a public getter of the bin width; added extern global gTMassPeakFit
normalised gauss definition: multiplying the prefactor by the bin width so that the parameter is number of events
changed variable name area to nevents;  changed parameter names
changed GLOBAL_INSTANCE to gTMassPeakFit - ROOT style for global instances
moved global instance definition to class source file
rewrote pieces of code such that they are valid for generic function, not only pol3
changed the calculation procedure for negative log likelihood - taking logarithm for each term...
added new option to the config file - normalised gaussian or not. removed normalized_gaussian config file since it becomes obsolete with this option