Added a drupal alter in xml_form_builder_get_form to allow for the form ...

Added a drupal alter in xml_form_builder_get_form to allow for the form builder schema to be modified after it's been added to the form array.  This is needed for the metrodora module to allow it to modify tab panel access permission to the form builder schema that's saved into the form array.
Bad resolution of merge conflict? Should probably avoid nuking...