FIX: using SwapBuffers instead of wglSwapBuffers and adding opengl.lib into systems definition for not VS builds

Author: Oldes

src/os/win32/host-event.c

@@ -49,9 +49,7 @@
 
 //OpenGL
 #pragma comment(lib, "opengl32")
-#pragma comment(lib, "glu32")
 #include <gl/gl.h>
-#include <gl/glu.h>
 
 //-- Not currently used:
 //#include <windowsx.h>
@@ -544,7 +542,7 @@ static REBINT Check_Modifiers(REBINT flags)
 			glEnd();
 			glFlush();
 
-			wglSwapBuffers(hdc);
+			SwapBuffers(hdc);
 		//	wglMakeCurrent(hdc, 0);
 			EndPaint(hwnd, &ps);
 		return FALSE;

src/tools/systems.r

@@ -74,7 +74,7 @@ linker-flags: [
 	LLOG:	"-llog"						; on Android, link with liblog.so
 	ARC:	"-arch i386"				; x86 32 bit architecture (OSX)
 	M32:	"-m32"						; use 32-bit memory model (Linux x64)
-	W32:	"-lwsock32 -lcomdlg32 -lgdi32 -lwinmm -lComctl32 -lUxTheme"
+	W32:	"-lwsock32 -lcomdlg32 -lgdi32 -lwinmm -lComctl32 -lUxTheme -lopengl32"
 	WIN:	"-mwindows"					; build as Windows GUI binary
 	CON:	"-mconsole"					; build as Windows Console binary
 	S4M:	"-Wl,--stack=4194300"