Consider an overload for BarGraph that takes OpenCV.Mas as input

[bruno-f-cruz]

This would be very useful for histogram-like visualizations.

[glopesdev]

@bruno-f-cruz to avoid taking a dependency from OpenCV we could probably make it with an array overload and just use ConvertToArray before sending it to the graph. In fact, I didn't try it, but maybe this already works?