Native javascript

This pull request removes jQuery as a dependency.  This is a large rewrite, but it will result in huge performance gains as well as lowering the requirements to include JSON editor in an existing project.  After this, the project will have no required dependencies!

Working:
*  validation
*  ajax
*  array, multiple, object, select, integer, number, and string editors
*  html theme

Not working yet:
*  table, enum, and null editors
*  bootstrap, foundation, and jqueryui themes
*  iconlibs
*  need non-jquery implementations of $.each, $.extend, and el.data
*  need way to instantiate and use the api without $.fn.extends

Once everything is implemented:
*  testing!!!
*  performance benchmarks compared to existing library
*  rewrite demo page and examples in native javascript
*  update README