String.prototype.basename

@Description: Grabs the basename from a url
@File: String/prototype/basename.js
@Author: Paul Visco
@Version: 1.0 11/19/07
@Return: String The filename part of the original string
@Example:

var myString = 'http://www.google.com/logo.gif';
var newString = myString.basename();
//newString = 'logo.gif';