Tentatively implemented the vertical scrolling part of EGA and (S)VGA CRTC register 8;

PCap devices list generator now aborts if WinPcap is not present;
Fixed the CD-ROM START STOP UNIT command;
More preparations for SCSI removable hard disks.

src/cdrom.c

@@ -3100,7 +3100,7 @@ void cdrom_command(uint8_t id, uint8_t *cdb)
 			break;
 
 		case GPCMD_START_STOP_UNIT:
-			switch(cdbufferb[4] & 3)
+			switch(cdb[4] & 3)
 			{
 				case 0:		/* Stop the disc. */
 					if (cdrom_drives[id].handler->stop)