Handle CloneNotSupportedException in a standard and most-correct way.

git-svn-id: svn+ssh://src.earth.threerings.net/nenya/trunk@17 ed5b42cb-e716-0410-a449-f6a68f950b19

src/java/com/threerings/miso/data/SparseMisoSceneModel.java

@@ -223,8 +223,7 @@ public class SparseMisoSceneModel extends MisoSceneModel
                 section.objectInfo = (ObjectInfo[])objectInfo.clone();
                 return section;
             } catch (CloneNotSupportedException cnse) {
-                throw new RuntimeException(
-                    "SparseMisoSceneModel.Section.clone: " + cnse);
+                throw new RuntimeException(cnse);
             }
         }