Add pre_ent2ncr filter. props GaryJ, fixes #16432.

git-svn-id: https://develop.svn.wordpress.org/trunk@18456 602fd350-edb4-49c9-b593-d223f7449a82

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(
 		'"' => '"',
 		'&' => '&',