Fixed MCA write bugs for the AHA-1640 and BT-640;
Fixed a warning in the PC87306 Super I/O chip emulation;
Each renderer now only has a 32-bit blitter - video_blit_memtoscreen_8() now only converts buffer to buffer32 and then calls video_blit_memtoscreen(), 8-bit blitters are now gone.
Fixed the Force 4:3, Enable EGA/(S)VGA overscan, and Scale options;
Fixed a bug regarding register 0 of the SMC FDC37C665 Super I/O chip;
Commented out some excess logging.
The Settings dialog now correctly filters devices by bus;
Split the dual VLB/PCI graphics cards into VLB and PCI versions;
Device filtering is now done using the new device_is_valid() call that compares device flags to machine flags;
Moved the NCR-based SCSI controllers to the main branch;
Moved the NE1000 to the dev branch until it's finished.
