fix for Google+

Google+ uses some CSS class names that MathJax also uses, since they're the names of MathML elements.
This version appends a style tag to the page to override Google+'s styles and make the MathJax elements inherit the styles of their parents, as MathJax assumes should be the case.
add install page
whoops, index.html was already the install page
add AsciiMath processor
tidy up demo page
readme links to my install page

because dzejkej's one is out of date.
Merge branch 'gh-pages'

Conflicts:
	README.md
Merge pull request #3 from christianp/master

Add fix for Google+