Clear out original-to-copy mapping after creating copy so that we don't

prevent the last copy from being garbage collected.


git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@4156 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/java/com/threerings/jme/model/Model.java

@@ -911,7 +911,9 @@ public class Model extends ModelNode
         public Spatial createCopy ()
         {
             random = RandomUtil.getInt(Integer.MAX_VALUE);
-            return super.createCopy();
+            Spatial copy = super.createCopy();
+            originalToCopy.clear(); // make sure no references remain
+            return copy;
         }
     }