The WinSock library is now loaded at run-time, which means we can

attempt to load WS2 and then fall back to WS1 if that fails. This
should allow us to use WS2-specific functionality to find out the
local system's list of IP addresses, thus fixing winnet-if2lo, while
degrading gracefully back to the previous behaviour if that
functionality is unavailable. (I haven't yet actually done this; I've
just laid the groundwork.)
This checkin _may_ cause instability; it seemed fine to me on
initial testing, but it's a bit of an upheaval and I wouldn't like
to make bets on it just yet.

[originally from svn r3502]

console.c

@@ -3,8 +3,6 @@
  * the console PuTTY tools
  */
 
-#include <windows.h>
-
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdarg.h>
@@ -26,7 +24,6 @@ void cleanup_exit(int code)
      * Clean up.
      */
     sk_cleanup();
-    WSACleanup();
 
     random_save_seed();
 #ifdef MSCRYPTOAPI