[development] += on arrays

[Jeff Robbins]

So does this mean that we can do:

   $form['foo'] = array('a' => 'b', 'c' => 'd');
   $form['foo'] += array('a' => 'new b', 'e' => 'f');

instead of:

   $form['foo'] = array('a' => 'b', 'c' => 'd');
   $form['foo'] = array_merge($form['foo'], array('a' => 'new b', 'e'  
=> 'f'));

???

With the intense use of arrays in the new form api that sure would be  
nice.

-jeff