Update is(). Argument can take more than one element. Closes jquery#415

Author: AurelioDeRosa

entries/is.xml

@@ -21,8 +21,8 @@
   </signature>
   <signature>
     <added>1.6</added>
-    <argument name="element" type="Element">
-      <desc>An element to match the current set of elements against.</desc>
+    <argument name="elements" type="Element">
+      <desc>One or more elements to match the current set of elements against.</desc>
     </argument>
   </signature>
   <desc>Check the current matched set of elements against a selector, element, or jQuery object and return <code>true</code> if at least one of these elements matches the given arguments.</desc>