Add MathJax repository as submodule

* Adds the nodejs branch of MathJax as submodule
* Now a running version can be cloned with the
  --recursive option
Update reference to MathJax dev branch
return error message in case of invalid format
Add support for speech-rule-engine.  Add dpi control for image generation.  Add option to make unknown characters not be listed in error array.  Allow control of semantics annotation creation.  Update command-line tools to include more options and use yargs to process them (for better help).  This allows several separate tools to be combined into one (with options).
Merge pull request #14 from physikerwelt/InvalidFormat

Return error message in case of invalid format
Merge pull request #13 from physikerwelt/GitSubModule

Git sub module for MathJax.
Add callback support to ReportError as in mj-single.js
Update use of outerHTML to accommodate changes in jsdom v1.0
Updated MathJax to current develop version
Updated MathJax to current develop version
Fix PNG rendering outside of root directory.

This commit references the `batik-rasterization.jar` file by its full
path, calculated based on the root MathJax-node directory's location.
This allows users to call the library from any directory and render
.pngs as expected.
Use path.resolve to find MathJax.js, and fix up formatting.
Don't try to find the SVG element if there isn't going to be one.
Get correct ID for title and desc elements in SVG output with speech.  Resolves issue #29.
Merge branch 'issue29'