Add coloring table cells by value

[dbosak01]

It would be awesome to be able to color cells in a table by value. For example, specifying one column that 0% is dark red, 0-50% is bright red, 50-80% is orange, 80-90% is yellow and 90%+ is green. Another may be more arbitrary, 0-5 red, 5-10 yellow, 10-15 green.

I have been kludging together html reports for coming up on 10 years using ggplot2 and xtable and coming up with clever regular expressions to color cells and I'm excited that this may be a far more easily maintained, far more modular and far quicker to develop methodology.