jQuery function for parsing URL parameters
MIT-License: http://www.opensource.org/licenses/mit-license.php
$.urlParams("get", "param_name") // => returns unescaped string of the parameter "param_name"
$.urlParams("keys") // => returns an array of all parameter keys
$.urlParams("exists", "param_name") // => returns true if "param_name" exists; false otherwise
$.urlParams("all") // => returns a hash with all key, value pairs