Fixed Sound Blaster 16 and earlier CD-ROM volume registers (and made them no longer default to 0);
Serial mouse now resets the FIFO before sending the ID, fixes mouse detection after clipping and moving the mouse;
Rewritten CD-ROM and SCSI disk Mode Select handling and changed things regarding Mode Sense as well, also fixes emulator segmentation faults when anything attempts to do a Mode Select;
Fixed the Microsoft InPort mouse emulation (used the Bochs code as reference for the polling/state update code), now it actually moves;
The PCjr initialization now sets the XT scan code table, makes the keyboard actually work on the PCjr again;
Several bugfixes regarding the Read CD commands, fixes CD Audio in digital mode on Windows ME;
Finally properly fixed the regular CD Audio MSF/LBA conversion mess;
Applied all applicable PCem commits.
Re-worked the system pathnames (pc.c), renamed cfg_path to usr_path.
Other small things here and there.
Logitech bus mouse re-worked, should be OK now.
IBM.H is gone, video stuff re-organized. Keyboard stuff reorganized.
Machines that have their own video, mouse and/or keyboard now have all this in their machine file.
Fixed and other cleanups here and there.
