fully ignore screen-off bit (fixes Darklands, Skyroads3d)

git-svn-id: https://dosbox.svn.sf.net/svnroot/dosbox/dosbox/trunk@2828 67dff46e-583c-4055-8ee1-d6b00ecfda6c

Author: c2woody

src/hardware/vga_seq.cpp

@@ -40,7 +40,9 @@ void write_p3c5(Bitu port,Bitu val,Bitu iolen) {
 	case 1:		/* Clocking Mode */
 		if (val!=seq(clocking_mode)) {
 			seq(clocking_mode)=val;
-			VGA_StartResize();
+			// don't resize if only the screen off bit was changed
+			if ((val&(~0x20))!=(seq(clocking_mode)&(~0x20)))
+				VGA_StartResize();
 		}
 		/* TODO Figure this out :)
 			0	If set character clocks are 8 dots wide, else 9.