win32: define _WIN32_WINNT globally

Rather than defining _WIN32_WINNT only in a handful of files, define
it in config.h, like we do with _GNU_SOURCE.

(Also remove a "#define WIN32_LEAN_AND_MEAN" that isn't really all
that useful.)

https://bugzilla.gnome.org/show_bug.cgi?id=688109

configure.ac

@@ -150,6 +150,8 @@ case "$host" in
       LIB_EXE_MACHINE_FLAG=X64
       ;;
     esac
+
+    AC_DEFINE([_WIN32_WINNT], [0x0501], [Target the Windows XP API])
     ;;
   *)
     glib_native_win32=no

gio/glocalfile.c

@@ -66,7 +66,6 @@
 #include "glibintl.h"
 
 #ifdef G_OS_WIN32
-#define _WIN32_WINNT 0x0500
 #include <windows.h>
 #include <io.h>
 #include <direct.h>

gio/gnetworkingprivate.h

@@ -23,7 +23,6 @@
 
 #ifdef G_OS_WIN32
 
-#define _WIN32_WINNT 0x0501
 #include <winsock2.h>
 #undef interface
 #include <ws2tcpip.h>

gio/gregistrysettingsbackend.c

@@ -97,9 +97,6 @@
 #include "gsettingsbackend.h"
 #include "giomodule.h"
 
-
-#define _WIN32_WINNT 0x0500
-#define WIN32_LEAN_AND_MEAN
 #include <windows.h>
 
 //#define TRACE

gio/gtestdbus.c

@@ -45,7 +45,6 @@
 #include "glibintl.h"
 
 #ifdef G_OS_WIN32
-#define _WIN32_WINNT 0x0500
 #include <windows.h>
 #endif
 

gio/gwin32volumemonitor.c

@@ -35,7 +35,6 @@
 #include "gmount.h"
 #include "giomodule.h"
 
-#define _WIN32_WINNT 0x0500
 #include <windows.h>
 
 struct _GWin32VolumeMonitor {

gio/win32/gwin32directorymonitor.c

@@ -21,8 +21,6 @@
  * 
  */
 
-#define _WIN32_WINNT 0x0400
-
 #include "config.h"
 #include "gwin32directorymonitor.h"
 #include <windows.h>

gio/win32/gwinhttpvfs.h

@@ -28,7 +28,6 @@
 #include <gio/giotypes.h>
 #include <gio/gvfs.h>
 
-#define _WIN32_WINNT 0x0500
 #include <windows.h>
 
 #include "winhttp.h"