Enforced the inclusion of windows headers before nethack headers.

Moved the code page 437 mapping table to winnt.c so that it could be
used in window and console clients.
Added check that fonts support unicode values we use from code page 437.
Use unicode to draw text if font supports it otherwise use ASCII.

sys/winnt/nhraykey.c

@@ -160,9 +160,9 @@
 static char where_to_get_source[] = "http://www.nethack.org/";
 static char author[] = "Ray Chason";
 
+#include "win32api.h"
 #include "hack.h"
 #include "wintty.h"
-#include "win32api.h"
 
 extern HANDLE hConIn;
 extern INPUT_RECORD ir;