Revert "Add htmlSpecialChars"

This reverts commit 41ed0c18e4.

h5p.classes.php

@@ -1526,7 +1526,7 @@ class H5PCore {
 
   public static $coreApi = array(
     'majorVersion' => 1,
-    'minorVersion' => 4
+    'minorVersion' => 3
   );
   public static $styles = array(
     'styles/h5p.css',

js/h5p.js

@@ -1099,10 +1099,3 @@ if (H5P.jQuery) {
     }
   });
 }
-
- /**
-  * Mimics how php's htmlspecialchars works (the way we use it)
-  */
-H5P.htmlSpecialChars = function(string) {
-  return string.toString().replace(/</g, '&lt;').replace(/>/g, '&gt;').replace(/'/g, '&#039;').replace(/"/g, '&quot;');
-};