Fixes to various hard disk controllers;
Added the Packard Bell PB640;
Fixed the InPort mouse emulation - now it works correctly on Windows NT 3.1;
Removed the status window and the associated variables;
Completely removed the Green B 486 machine;
Fixed the MDSI Genius;
Fixed the single-sided 5.25" floppy drive;
Ported a CPU-related commit from VARCem.
Merged floppy.c and fdd.c and renamed floppy_*.c (the floppy image format handlers) to fdd_*.c;
Reading the AT or PS/2 keyboard controller status no longer clears the transmit timeout bit, fixes error 8601 (mouse error) on the IBM PS/2 Model 80;
MMU translate and DMA physical reads and writes now go through _mem_exec instead of directly to ram[], should fix the last remaining problems with remapped mappings;
Implemented the Sound gain dialog;
Added the resource for the "New floppy image" dialog and the needed functions for the functionality of exporting the currently mounted floppy image as 86F, both of which should be finished in the next commit;
Applied the CD-ROM fixes from the PCem commit;
Added the "Keep ratio" option for full screen stretch.
The "Write data to mouse" command no longer times out when there is PS/2 mouse, and instead adds the 0xFF byte to the queue, properly fixes the hang when entering into the P55T2S BIOS' CMOS Setup with mouse set to anything other than PS/2;
Removed the incorrect implementation of the OPTi 495 register 0x27 bit 7, it had nothing to do with A20, and the A20 stuck error was caused by the previously incorrect implementation of the 8042 output port bit pulse commands which is no longer the case;
The 8042 now once again correctly initializes with A20 Gate on.
Fixed a bug in the SMC FDC37C932 emulation, fixes the FDC on the two Acer machines;
Re-added some Acer-specific I/O port handlers, fixes entry into CMOS Setup on the two Acer machines.
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.
