Release port on close

Helps with the Python module when an object gets deleted.
Bug-Debian: http://bugs.debian.org/461068

Gbp-Pq: Name release_on_close.patch

src/interface.c

@@ -62,6 +62,7 @@ ieee1284_close (struct parport *port)
       debugprintf (needs_open_port, "ieee1284_close");
       return E1284_INVALIDPORT;
     }
+  ieee1284_release(port);
   if (priv->fn->cleanup)
     priv->fn->cleanup (priv);
   priv->opened = 0;