Add mathjax to runtime.
Add WYSIWYG editor, and math typography support.

[#57226316]
[#67313302]

https://www.pivotaltracker.com/story/show/57226316
https://www.pivotaltracker.com/story/show/67313302
Bump smartgraphs runtime, w/ support mathjax & bullet lists in intro txt

https://www.pivotaltracker.com/story/show/57226316 [#57226316]
https://www.pivotaltracker.com/story/show/67313302 [#67313302]