fix github issue 361 to make user_sounds useful even if MSGTYPE is hidden

fixes #361

Also, experminental introduction of vt_sounddata to enable tty to pass
a sound file index to the terminal side of things where perhaps someone
can add code to something like hterm to take the information relayed by
NetHack to trigger user_sounds locally even if playing on a server.

Compile time option TTY_SOUND_ESCCODES required to build that support in.

It should be independent of TTY_TILE_ESCCODES.

sys/winnt/stubs.c

@@ -189,4 +189,13 @@ set_altkeyhandler(const char *inName)
 {
     return;
 }
+
+#if defined(USER_SOUNDS) && defined(TTY_SOUND_ESCCODES)
+void
+play_usersound_via_idx(idx, volume)
+int idx, volume;
+{
+}
+#endif /* USER_SOUNDS && TTY_SOUND_ESCCODES */
+
 #endif /* TTYSTUBS */