#22. Added drupalgap_remove_page_from_dom() and changed drupalgap_goto() to use it. Added drupalgap_entity_edit_form_cancel_button(). Added drupalgap_entity_edit_form_delete_button() and drupalgap_entity_edit_form_delete_confirmation(). Added drupalgap_services_get_entity_resource() and changed drupalgap_entity_form_submit() to use it. Changed node, vocabulary and term edit forms to use the new cancel and delete button mechanisms.