disable mactype for DCs with color lower than 24bit.

This walkaround the issue #440.
I can't call it a solution, but most programs today runs under 24bit or 32bit graphic mode, so it should not matter much. And those 16bit programs, they should be able to stay in the degraded cleartype mode safe enough.

override.cpp

@@ -1314,7 +1314,7 @@ ETO_TRY();
 	BITMAP bm;
 	HBITMAP hbmpSrc = (HBITMAP)GetCurrentObject(hdc, OBJ_BITMAP);
 
-	if(hbmpSrc && ORIG_GetObjectW(hbmpSrc, sizeof(BITMAP), &bm) && bm.bmBitsPixel == 1) {
+	if(hbmpSrc && ORIG_GetObjectW(hbmpSrc, sizeof(BITMAP), &bm) && bm.bmBitsPixel <= 16) {
 		//ﾗﾔｶｯﾉ靹ﾃﾎｪｵ･ﾉｫ葷ﾈｾｷｽﾊｽ
 		ETO_THROW(ETOE_MONO);	//ｲｻ葷ﾈｾｵ･ﾉｫﾎﾄﾗﾖ
 		//params.ftOptions |= FTO_MONO;