Notes on the M1,M2 data set ground truth files
 
- Each line describes a consensus feature
- Each consensus feature is given by the  intensity, rt, and m/z values of the assigned featuress well as the file name of the original feature file, score was set to zero:
"M1_1 0 intensity_feat_1 rt_feat_1 mz_feat_1 M1_2 0 intensity_feat_2 rt_feat_2 mz_feat_2 M1_3 0 intensity_feat_3 ..."
 - Single space is used as separator
 - We use the intensity, rt, and m/z value to uniquely identify the origin of a feature