Enable better build-time flexibility over which WinSock to include

[originally from svn r615]

Makefile

@@ -21,6 +21,15 @@
 #  - COMPAT=/DWIN32S_COMPAT
 #      Generates a binary that works (minimally) with Win32s.
 #
+#  - COMPAT=/DAUTO_WINSOCK
+#      Causes PuTTY to assume that <windows.h> includes its own WinSock
+#      header file, so that it won't try to include <winsock.h>.
+#
+#  - COMPAT=/DWINSOCK_TWO
+#      Causes the PuTTY utilities to include <winsock2.h> instead of
+#      <winsock.h>, except Plink which _needs_ WinSock 2 so it already
+#      does this.
+#
 #  - RCFL=/DASCIICTLS
 #      Uses ASCII rather than Unicode to specify the tab control in
 #      the resource file. Probably most useful when compiling with

plink.c

@@ -2,7 +2,9 @@
  * PLink - a command-line (stdin/stdout) variant of PuTTY.
  */
 
+#ifndef AUTO_WINSOCK
 #include <winsock2.h>
+#endif
 #include <windows.h>
 #include <stdio.h>
 #include <stdarg.h>

raw.c

@@ -1,7 +1,13 @@
 #include <windows.h>
 #include <stdio.h>
 #include <stdlib.h>
+#ifndef AUTO_WINSOCK
+#ifdef WINSOCK_TWO
+#include <winsock2.h>
+#else
 #include <winsock.h>
+#endif
+#endif
 
 #include "putty.h"
 

scp.c

@@ -9,7 +9,13 @@
  */
 
 #include <windows.h>
+#ifndef AUTO_WINSOCK
+#ifdef WINSOCK_TWO
+#include <winsock2.h>
+#else
 #include <winsock.h>
+#endif
+#endif
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>

ssh.c

@@ -2,7 +2,13 @@
 #include <stdlib.h>
 #include <stdarg.h>
 #include <assert.h>
+#ifndef AUTO_WINSOCK
+#ifdef WINSOCK_TWO
+#include <winsock2.h>
+#else
 #include <winsock.h>
+#endif
+#endif
 
 #include "putty.h"
 #include "tree234.h"

telnet.c

@@ -1,7 +1,13 @@
 #include <windows.h>
 #include <stdio.h>
 #include <stdlib.h>
+#ifndef AUTO_WINSOCK
+#ifdef WINSOCK_TWO
+#include <winsock2.h>
+#else
 #include <winsock.h>
+#endif
+#endif
 
 #include "putty.h"
 

windlg.c

@@ -1,7 +1,13 @@
 #include <windows.h>
 #include <commctrl.h>
 #include <commdlg.h>
+#ifndef AUTO_WINSOCK
+#ifdef WINSOCK_TWO
+#include <winsock2.h>
+#else
 #include <winsock.h>
+#endif
+#endif
 #include <stdio.h>
 #include <stdlib.h>
 

window.c

@@ -1,6 +1,12 @@
 #include <windows.h>
 #include <commctrl.h>
+#ifndef AUTO_WINSOCK
+#ifdef WINSOCK_TWO
+#include <winsock2.h>
+#else
 #include <winsock.h>
+#endif
+#endif
 #include <stdio.h>
 #include <stdlib.h>
 #include <ctype.h>