TikzPictures and PGFPlots packages

Created TikzPictures for creating Tikz pictures generated by lualatex. PGFPlots is a package built on top of TikzPictures for generating publication quality plots. See documentation here:
http://nbviewer.ipython.org/github/sisl/PGFPlots.jl/blob/master/doc/PGFPlots.ipynb