Peaks near the border of a bin are split

[elliotfontaine]

During feature extraction, some peaks located at either end of bins can get split because of how binning works. Intensity is lower than it should be.

BinneR gives a quality control metrics, "centrality", that can help mitigate this issue. If two neighbor bins have low centrality and assigned m/z values that are very close, then they should be merged: drop one on the two values, and sum the intensity.