Attempt to add support for jQuery 1.9.0 (needs testing)

Use jQuery.fn.addBack() instead of jQuery.fn.andSelf() when using jQuery
1.8.0 or newer. Also, since the jQuery.browser feature was removed,
demo\css3pie.html now uses JavaScript's built-in navigator option to
detect MSIE version < 7.

See [issue #8][https://github.com/dreamerslab/jquery.actual/issues/8]