Fix for `slow-startup-printer': use PRINTER_INFO_4 on NT-class systems, which

apparently tries less hard to find printers so won't slow the system down.

Tested on 2000 and 98; in both cases printer enumeration and printing worked
as well as they did in 2003-08-21.

Made a single shared copy of osVersion in winmisc.c so that printing.c can
find it. Made other users (window.c, pageant.c) use this copy.

[originally from svn r3411]

winmisc.c

@@ -8,6 +8,8 @@
 #include "putty.h"
 #include "winstuff.h"
 
+OSVERSIONINFO osVersion;
+
 void platform_get_x11_auth(char *display, int *proto,
                            unsigned char *data, int *datalen)
 {
@@ -88,6 +90,13 @@ void SaneEndDialog(HWND hwnd, int ret)
     SetWindowLong(hwnd, BOXFLAGS, DF_END);
 }
 
+BOOL init_winver(void)
+{
+    ZeroMemory(&osVersion, sizeof(osVersion));
+    osVersion.dwOSVersionInfoSize = sizeof (OSVERSIONINFO);
+    return GetVersionEx ( (OSVERSIONINFO *) &osVersion);
+}
+
 #ifdef DEBUG
 static FILE *debug_fp = NULL;
 static HANDLE debug_hdl = INVALID_HANDLE_VALUE;