move loadFromGraphite into DataCollection.
update ansi graph to have a title and legend.
draw a grid in the background.
refactoring, and a whole grid. not sure i like it.
clean up the grid.
allow a background color for the graph image.
allow svg to omit the legend.
add defaults and command-line app.
clean up colors a bit. expose svg. let legend be turned on/off.
tweak the colors, and allow choosing a theme.