ZF-2788: Add option to disable loading default decorators in Zend_Form
Currently, decorators for the various Zend_Form object are always loaded; default decorators exist and are loaded by default. In some cases, you may not want this: * If using Zend_Form in models for input filtering, and allowing re-purposing the model for use with a web service * When using Zend_Form::setElementDecorators() (no need to load decorators twice!) To accomplish this, a new flag should exist, 'loadDefaultDecorators'; when true (the default), the default decorators will be loaded; otherwise, they will not. Additionally, the protected _loadDefaultDecorators() method should be made public, to allow loading them on-demand.