Large changes to configuration files again (the old ones might break, be careful);

Applied the mainline PCem slight CPU emulation speedup commit;
Added emulation of removable SCSI hard disks;
CD-ROM image handler now uses C FILE's (with the 64-bit size calls) instead of C++ iostreams, ISO images bigger than 2 GB should work properly again;
Split RLL/ESDI and XT IDE disks to their own bus types;
Turned status bar pane meaning and hard disks and CD-ROM BUS numbers to #define's;
Other miscellaneous cleanups.

src/disc.c

@@ -130,7 +130,7 @@ void disc_load(int drive, wchar_t *fn)
         pclog_w(L"Couldn't load %s %s\n",fn,p);
         drive_empty[drive] = 1;
 	fdd_set_head(real_drive(drive), 0);
-        discfns[drive][0] = L'\0';
+	memset(discfns[drive], 0, sizeof(discfns[drive]));
 	update_status_bar_icon_state(drive, 1);
 }