Tikz -- proof of concept only -- don't pull into develop (yet) on openwebwork

[mgage]

This is pull request illustrates proof of concept for rendering tikz code within a WeBWorK project.

This branch is NOT ready for prime time and should not be pulled into develop(yet). We've place it here so you can take a look at it as it is developed. You can pull it into your local instances of WeBWorK ( split off from the develop branch) and see what you think of it.

There are two example problems in pg/t/tikz_test that show how it is used (at present). The user front end will probably change significantly as we get feedback.

$path = tikz_graph(<<END_TIKZ);
\begin{tikzpicture}[main_node/.style={circle,fill=blue!20,draw,minimum size=1em,inner sep=3pt]}] 
\draw (-4,0) -- (4,0);
\draw (0,-2) -- (0,2);
\draw (0,0) circle (1.5);
\draw (0, 1.5) node[anchor=south]{N} -- (2.5,0)node [above]{y};
\draw (1.2,0.9) node[right]{\((\vec x, x_{n})\)};
\end{tikzpicture}
END_TIKZ

This is work of Mike Gage and Peter Peluso at U. of Rochester, based on the initial perl script developed by Mathew Vassair working under the direction of Dr. Sternin and Dr. D'Agostino at Brock University.

[taniwallach]

I suspect that this PR is no longer needed.
We already merged #432 .

@mgage - Can this be closed?

[mgage]

I believe you are correct @taniwallach .