latex-docker simple secure versioned texlive

Based on v2.0.0 of https://github.com/blang/latex-docker, this is a significant rewrite to support maintaining the latex version with the project.

• Simple:: pdflatex paper.tex
• Secure: The only FROM that is not in your control is debian:jessie
• Maintainable: You can rebuild the base packages and maintain your changes
• Portable: Your document is managed along with the packages to build it
• Versioned: Each project has its own texlive version - sharing latex is now far less painful.