Oop, clear complex entries when we clear.

git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@4119 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/as/com/threerings/util/HashMap.as

@@ -17,6 +17,7 @@ public class HashMap
     public function clear () :void
     {
         _simpleData = null;
+        _entries = null;
         _size = 0;
     }