Kill all local variables on function return.  This closes a gigantic
leak of memory and file descriptors (thanks for Roj for reporting
that!).  Alas, the speed goes down by 5%. :-(
diff --git a/Python/ceval.c b/Python/ceval.c
index 651066c..3d2375c 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -1696,6 +1696,18 @@
 			why = WHY_EXCEPTION;
 		}
 	}
+
+	/* Kill all local variables */
+
+	{
+		int i;
+		for (i = co->co_nlocals; --i >= 0; ++fastlocals) {
+			if (*fastlocals != NULL) {
+				DECREF(*fastlocals);
+				*fastlocals = NULL;
+			}
+		}
+	}
 	
 	/* Restore previous frame and release the current one */