more consolidation of plot-util
consolidate arrays_as_d3 series
linegraph tag id no longer used in favor of "plot_div" id
conf argument to be standin for kwargs in javascript d3 plot functions bar_plot and line_plot
better modularity and OO for bar-plot and lag-plot
bump version
moved list_set to nlp.util from a views.py elsewhere
(c) year, and eliminate double requirement
hover style from bostock's bar chart tutorial