Don't undefine HAVE_MONITOR_INFO when compiling with gcc. Mingw's headers

Don't undefine HAVE_MONITOR_INFO when compiling with gcc. Mingw's headers

2004-03-13  Tor Lillqvist  <tml@iki.fi>

	* gdk/win32/gdkdisplay-win32.c: Don't undefine HAVE_MONITOR_INFO
	when compiling with gcc. Mingw's headers do have the required
	definitions.

	* gdk/win32/gdkdrawable-win32.c (draw_polygon): When drawing
	filled polygons, don't draw the outline, similarily as
	draw_rectangle(). Apparently GTK and GIMP don't use
	gdk_draw_polygon() much (or always draw the outline, too), as this
	has gone undetected for so long. Thanks to Bruce Hochstetler.