Expanded functionality to show global (all references) view.  In this view, all references are selected from the reference donut chart when the "All" link in the center of the chart is pressed.  The variant density for all references is shown in a linear area chart view, with chromosome bars below the chart functioning as an x-axis and selector.
Also had to introduce a few approaches to get point data to display in reasonable scale.  1) Placed a ceiling (top interquartile range) on "spiked" points and 2) Gathered data into n buckets to reduce point data to reasonable size.
Added newest test dataset.
Newest bar chart to show references below global density chart.  Needs to be refactored into generic bar chart class that allows for varying width rather than varying height.