Allow ARIA attributes in all elements

This allows any attribute that starts with aria- and contains only letters (which covers all existing aria attributes at this time).

helper.php

@@ -92,9 +92,14 @@ function buildAttributes($data, $myObj, $addClass='', $mode='xhtml') {
 
 					default:
 
-						/* special case: data- attributes: */
+						/* special case 1: data-* attributes: */
 						if (preg_match('/^data-[a-z][a-z0-9_-]*$/', $key)) {
-							$out .= ' '.$key.'="'.hsc(strtolower($val)).'"';
+							$out .= ' '.$key.'="'.hsc($val).'"';
+						}
+
+						/* special case 2: aria-* attributes: */
+						if (preg_match('/^aria-[a-z]+$/', $key)) {
+							$out .= ' '.$key.'="'.hsc($val).'"';
 						}
 
 						/* any other attribute: ask the class if it is allowed: */