Show exit status and time in the remain-on-exit pane text, mostly from

Timo Boettcher in GitHub issue 1103.

window.c

@@ -908,6 +908,7 @@ window_pane_spawn(struct window_pane *wp, int argc, char **argv,
 		free((void *)wp->cwd);
 		wp->cwd = xstrdup(cwd);
 	}
+	wp->flags &= ~(PANE_STATUSREADY|PANE_STATUSDRAWN);
 
 	cmd = cmd_stringify_argv(wp->argc, wp->argv);
 	log_debug("spawn: %s -- %s", wp->shell, cmd);