Support added for building using a GNU toolchain on Win32,

i.e. gcc -mno-cygwin on cygwin (a.k.a. mingw32, using egcs-1.1.2).

	* README.win32: Updated.
	* build-dll makefile.cygwin tests/makefile.cygwin: New files.
	* glib.h glib.def glibconfig.h.win32 makefile.msc: Slight updates.
	* gmain.c: No need to include <fcntl.h> and <io.h> on Win32.
	* gmain.c gutils.c testglib.c tests/string-test.c: Test for
	NATIVE_WIN32, not _MSC_VER.
	* gmutex.c: Must declare g_thread_functions_for_glib_use as
	exported (using the GUTILS_C_VAR macro).
	* gutils.c gmodule/libgplugin_[ab].c: LibMain not needed.
	* gmodule/gmoduleconf.h.win32: Need underscore with gcc.
	* gthread/gthread.c: With gcc on Win32, must use memcpy to assign
	value of g_thread_functions_for_glib_use (?).
	* makefile.msc tests/makefile.msc: Cosmetics.

glib/glib.h

@@ -2750,8 +2750,10 @@ GIOChannel *g_io_channel_win32_new_stream_socket (int socket);
  */
 #ifdef NATIVE_WIN32
 #  define MAXPATHLEN 1024
-#  ifdef _MSC_VER
+
+#ifdef _MSC_VER
 typedef int pid_t;
+#endif
 
 /* These POSIXish functions are available in the Microsoft C library
  * prefixed with underscore (which of course technically speaking is
@@ -2768,6 +2770,9 @@ typedef int pid_t;
 #    define getcwd		_getcwd
 #    define getpid		_getpid
 #    define access		_access
+#ifdef __GNUC__
+#    define stat		_stat
+#endif
 #    define open		_open
 #    define read		_read
 #    define write		_write
@@ -2802,7 +2807,6 @@ DIR*		gwin_opendir	(const gchar	*dirname);
 struct dirent*	gwin_readdir  	(DIR		*dir);
 void		gwin_rewinddir 	(DIR		*dir);
 gint		gwin_closedir  	(DIR		*dir);
-#  endif /* _MSC_VER */
 #endif	 /* NATIVE_WIN32 */