Stroke and Fill types

[tbreloff]

Right now I've got styles, colors, sizes, and opacity all defined separately, but it might be nice to have internal types Stroke and Fill which hold this info so that I can dispatch on them.

[tbreloff]

I decided to keep all components separate internally, but added user-facing stroke (mapping to lines and marker borders) and brush (mapping to area fills and markers), and improved the "magic args":

using Plots
gadfly()
plot(rand(10), l=(3,brush(0,:orange)), m=(20,0.5,:darkgreen,stroke(5,:green)))