refactor left hand gutter
refactor left hand gutter

igvteam/igv.js,igvteam/igv.js,NabaviLab/CNV-Visualizer,NabaviLab/CNV-Visualizer,NabaviLab/CNV-Visualizer,NabaviLab/CNV-Visualizer,NabaviLab/CNV-Visualizer