BUG 8529 Change "exists" to "exist" in many phrases SOLVED

- Remember these grammar rules
- Changed grammar rules as suggested.

workflow/engine/methods/cases/caseNotesAjax.php

@@ -7,7 +7,7 @@ if (!isset($_REQUEST ['action'])) {
 }
 if (!function_exists($_REQUEST ['action'])) {
   $res ['success'] = 'failure';
-  $res ['message'] = 'The requested action doesn\'t exists';
+  $res ['message'] = 'The requested action does not exist';
   header("Content-Type: application/json");
   print G::json_encode($res);
   die ();