Added Calendars.withCopy() at Jamie's request.

git-svn-id: https://samskivert.googlecode.com/svn/trunk@2633 6335cc39-0255-0410-8fd6-9bcaacd3b74c

src/java/com/samskivert/util/Calendars.java

@@ -159,6 +159,14 @@ public class Calendars
         return new Builder(calendar);
     }
 
+    /**
+     * Returns a fluent wrapper around a clone of the supplied calendar.
+     */
+    public static Builder withCopy (Calendar calendar)
+    {
+        return new Builder((Calendar)calendar.clone());
+    }
+
     /**
      * Returns a fluent wrapper around a calendar obtained with {@link Calendar#getInstance}.
      */