Ahodges/doc/doc1119

@shnayder @WatsonEmily @dsjen @srpearce @stroilova here's the initial draft for the gender demographic data. I don't have access to real data yet, so can't quite finish up the screen-shot-and-its-interpretation piece. (Suggestions on a good illustration welcome)
I'm not sure what this last sentence means - does edX try to map the new choice labels to the old choice labels, for example?