Fix for WikiEditor iframe extension on IE: use $.inArray() instead of Array.indexOf(), which is not in earlier JS standards as implemented in IE 8.

Use of Array.indexOf was added in r74271 when the iframe bits were broken out to an extension.

modules/jquery.wikiEditor.js

@@ -606,7 +606,7 @@ if ( args[0] == 'addModule' && typeof args[1] != 'undefined' ) {
 			for ( var e in $.wikiEditor.extensions ) {
 				if (
 					$.wikiEditor.isRequired( $.wikiEditor.modules[module], e ) &&
-					context.extensions.indexOf( e ) === -1
+					$.inArray( e, context.extensions ) === -1
 				) {
 					context.extensions[context.extensions.length] = e;
         			$.wikiEditor.extensions[e]( context );