Let's pass the triggering exception in there as well.

git-svn-id: https://samskivert.googlecode.com/svn/trunk@2486 6335cc39-0255-0410-8fd6-9bcaacd3b74c

src/java/com/samskivert/util/Histogram.java

@@ -109,7 +109,7 @@ public class Histogram
             chisto._buckets = _buckets.clone();
             return chisto;
         } catch (CloneNotSupportedException cnse) {
-            throw new AssertionError();
+            throw new AssertionError(cnse);
         }
     }