T tracer: add option to have both T traces and regular console logs

Use --T_stdout 2 to have both.

--T_stdout 0 is still the way to have only T traces and no console logs.

common/utils/T/T.c

@@ -217,6 +217,11 @@ void T_Config_Init(void) {
                          sizeof(ttraceparams) / sizeof(paramdef_t),
                          NULL);
 
-  if (T_stdout == 0)
+  if (T_stdout < 0 || T_stdout > 2) {
+    printf("fatal error: T_stdout = %d but only values 0, 1, or 2 are allowed\n", T_stdout);
+    exit(1);
+  }
+
+  if (T_stdout == 0 || T_stdout == 2)
     T_init(T_port, 1-T_nowait, T_dont_fork);
 }