I6 library appears to be lacking ClearScreen function

[joshwarecom]

While I7 does support Vorple clearing the screen, it appears that function is missing from the Inform 6 library. Something like this added to vorple-screen-effects.h should do the trick:

    VorpleClearScreen [;
      ClearScreen();
      VorpleExecuteJavaScriptCommand("$('#window0 *:not(.turn.current), .turn.current').empty()");
    ],