HTML5 and ES5 shim.

TODO:

• Replace reserved words, eg. "throw" with [...] notation to prevent syntax errors in IE (FF, Chrome etc. all support this) eg. "object.throw();", "object.instanceof();"
  • Would fix https://github.com/chaijs/chai/issues/7
• Hook eval() to filter JS
• Remove execScript() in IE (non-standard)
• Replace DOM with virtual DOM in IE
  • It may be possible to do all this without having to replace the DOM - hooking property/method accesses could be enough