/*
 *  Given the following url: http://www.example.net/#!&foo=bar&array[]=1&array[]=2
 */
 
hash('foo'); // 'bar'
hash('array'); // ['1', '2']
hash(); // { foo: 'bar', array: ['1', '2'] }

// Results in http://www.example.net/#!&foo=bar
hash('foo', 'bar');

// Results in http://www.example.net/#!&foo[]=bar&foo[]=baz
hash('foo', ['bar', 'baz']);

// Results in http://www.example.net/#!
hash('foo', undefined);