Fixed the last remaining ATAPI DMA bugs;
Fixed IDE hard disk DMA;
Fixed PIIX bus master DMA read and write;
The Settings dialog now accepts more than 16 heads for IDE hard disks;
Added the IDE READ DMA ALT and WRITE DMA ALT commands;
Reenabled current CHS translation reporting, with bugfixes, hopefully the bugfixes will prevent certain larger hard disks from being detected as 250 MB.
The CD-ROM buffer is now dynamically malloc'd;
Did a lot of bugfixing in cdrom.c and scsi_disk.c, Debian 8's modprobe aha1542 and the NT 3.10.404.1 Trantor 310b driver now work;
Fixed the IDE IRQ/MIRQ mess and ATAPI DMA transfer length;
Fixed the operation of mmutranslate() a bit;
Commented out several instances of excess logging;
Applied the mainline PCem commit prefetch commit;
Readded missing Sound Blaster DSP MIDI behavior and gave it the correct MPU struct;
All non-IBM 486 machines now correctly have the VLB flag set.
