off: add .off(Event_object) signature

Fixes jquerygh-384
Closes jquerygh-634

Author: AurelioDeRosa

entries/off.xml

@@ -24,6 +24,12 @@
       <desc>A selector which should match the one originally passed to <code>.on()</code> when attaching event handlers.</desc>
     </argument>
   </signature>
+  <signature>
+    <added>1.7</added>
+    <argument name="event" type="Event">
+      <desc>A <a href="/category/events/event-object/"><code>jQuery.Event</code></a> object.</desc>
+    </argument>
+  </signature>
   <signature>
     <added>1.7</added>
   </signature>