copy ctop.js into the content-mathml extension

Developed in mathjax/ctop. Uses the MathML jax's DOMfilterHooks to manipulate MathML elements before they're parsed into the internal format.
Content-MathML extension: update CToP.js

from mathjax/ctop
content-mathml extension: load config from MathJax.Hub.Config

Config is loaded from `MathML.content-mathml`, and extends the CToP.settings object.
content-mathml: make it compatible with IE8; code style fixes
Merge remote-tracking branch 'mathjax/develop' into ctop

Conflicts:
	unpacked/extensions/MathML/content-mathml.js
Merge pull request #806 from christianp/ctop

Use ctop.js instead of XSLT in Content MathML extension.

Finally getting to merge this.  At long last!