Support XDM-AUTHORIZATION-1 for connecting to local X servers. If

we're going to be a security program, we can at least make a token
effort to use the most secure local X auth available! And I'm still
half-tempted to see if I can support it for remote X servers too...

[originally from svn r2537]

winstuff.h

@@ -88,6 +88,15 @@ GLOBAL void *logctx;
  */
 #define SEL_NL { 13, 10 }
 
+/*
+ * sk_getxdmdata() does not exist under Windows (not that I
+ * couldn't write it if I wanted to, but I haven't bothered), so
+ * it's a macro which always returns FALSE. With any luck this will
+ * cause the compiler to notice it can optimise away the
+ * implementation of XDM-AUTHORIZATION-1 in x11fwd.c :-)
+ */
+#define sk_getxdmdata(socket, ip, port) (0)
+
 /*
  * Exports from winctrls.c.
  */