Add missing use statement for Zend_View_Abstract
Rename Form::addElement to Form::createElement

Since we are using mainly createElement and addElement is only an alias for
createElement if no object is passed our changes to addElement can safely
be moved to createElement.

refs #5525
Do not consider <button type=submit> when checking form completion

refs #5525
Drop ReorderForm and handle its logic in the controller and view instead

refs #5525