Feature/precursor scoring

Allow OpenSWATH to also extract the precursor ion trace from a dataset (from the MS1 map) and compute a set of scores based on the precursor data. Currently these scores include

- shape and coelution score with the monoisotopic precursor trace in MS1
- delta ppm score between the theoretical and the experimental value in MS1
because the function doesnt exist any more ... first I had a function calld getMS1Chromatogam but that would only store one chromatogram, so now I store multiple precursor chromatograms (for all isotopes for example) and the function is named getPrecursorChromatogram. I guess that was the last leftover from the first implementation, I will remove it