.is(): Refer to 2nd argument of function argument. Fixes jquery#512. Closes jquery#517

Author: AurelioDeRosa

entries/is.xml

@@ -10,7 +10,7 @@
   <signature>
     <added>1.6</added>
     <argument name="function" type="Function">
-      <desc>A function used as a test for the set of elements. It accepts one argument, <code>index</code>, which is the element's index in the jQuery collection. Within the function, <code>this</code> refers to the current DOM element. </desc>
+      <desc>A function used as a test for every element in the set. It accepts two arguments, <code>index</code>, which is the element's index in the jQuery collection, and <code>element</code>, which is the DOM element. Within the function, <code>this</code> refers to the current DOM element.</desc>
       <argument name="index" type="Integer" />
       <argument name="element" type="Element" />
       <return type="Boolean" />