Add full sound support

[TomAwezome]

• [ ] HDAudio driver
  • [x] Functional on Thinkpad T420
  • [ ] Functional on Gigabyte H110M-M2-CF motherboard
  • [ ] Functional on QEMU
  • [ ] Functional on Virtualbox
  • [ ] Functional on VMWare
• [ ] AC97 driver
  • [x] Functional on QEMU
  • [x] Functional on Virtualbox
  • [ ] Functional on VMWare
• [ ] Sound Subsystem
  • [ ] Implement new multi-driver sound system
  • [ ] Test new sound system functionality
  • [ ] Replace old sound system with new system
    • [ ] Update all Games and Demos to use new sound system
  • [ ] Test all Games and Demos with new sound system functionality
  • [ ] Document new sound system and both sound drivers