added new columns and data to data JSON file.
Created working engine constructor function with generalized filter that works with an arbitrarily large collection of series.
Created basic test case using old data in index.html. Have filter functionality that is independent of the number of series added to the input data.
Added generalized plotting for the seriesPlot and the filterPlot. Interactivity and histograms need more work.
Added bits to Engine object method that generalizes the plot for the results histogram.
Cleaned up dragger() and zoomer() global functions. dragger() works.
Added transition animation for barchart.
dataset now references json file.
Minor cleanup before merge back into master branch.