Freeing vector-space objects, apparently good.

Not freeing enough cons-space objects, though!

src/memory/vectorspace.c

@@ -67,6 +67,7 @@ struct cons_pointer make_vso( char *tag, uint64_t payload_size ) {
     struct vector_space_object *vso = malloc( padded );
 
     if ( vso != NULL ) {
+        memset(vso, 0, padded);
         debug_printf( DEBUG_ALLOC,
                       L"make_vso: about to write tag '%s' into vso at %p\n",
                       tag, vso );