Data model and plotting update

Now with "high level" support

Both the data model and the plot engine now support an separate color style for high level CNV events. In histograms those are overplotted on the standard color scheme - e.g. red areas where high level plots were detected, by their absolute frequency. In the example plot above we performed a search for high-level gains involving EGFR, in glioblastomas, and then only plotted chromosomes 7 and 9. While the ~100% peak at EGFR is expected, additionally nearly 70% of the matched samples have a focal and high level deletion involving the CDKN2A locus.