add click by button title (#4586)

Author: gimler

tests/data/app/view/form/anchor.php

@@ -7,6 +7,7 @@
 <form action="#a" method="post">
  <input name="field1" />
  <input type="submit" value="Hash Form" />
+ <button type="submit" title="Hash Button Form"></button>
 </form>
 
 <a href="#b">Hash Link</a>