Add pre_ent2ncr filter. props GaryJ, fixes #16432.

git-svn-id: http://svn.automattic.com/wordpress/trunk@18456 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/formatting.php

@@ -1875,6 +1875,10 @@ function wp_trim_excerpt($text) {
  * @return string Text with converted entities.
  */
 function ent2ncr($text) {
+
+	if( null !== $filtered = apply_filters( 'pre_ent2ncr', null, $text ) )
+		return $filtered;
+
 	$to_ncr = array(
 		'"' => '"',
 		'&' => '&',