If POST is rerun, try to do a machine reboot.

Add int 0x1589 support.

Review changes committed to coreboot, virtualbox, qemu, kvm, and bochs
cvs tip.
  * bochs cvs (20091017):
    -- 32bit pcibios, int1589
  * coreboot (r3348):    (bochs 20060708)
    -- no noteworthy enhancements
  * qemu (da5ff65d):     (bochs 20090210)
    -- changes synched
  * kvm (e5c31442):      (bochs 20090210)
    -- tpr patching, 16MB rom, acpi-ssdt.dsl, 4K aligned pci mem
  * virtualbox (r13560): (bochs 20061231)
    -- lots of mouse changes, logo, scsi/etherboot hooks, int 1589,
       floppy data rate?, int19 calls post

Audit all sti/cli calls.  Audit all call16 calls to make sure flags is
setup properly with respect to irqs.

The __call16 code does a long jump to the interrupt trampolines - this
is unnecessary.

Possibly implement 32bit pcibios support.

Support PCIv3 roms?  Add support for PCI "configuration code"
extensions?

Possibly add option to eliminate tsc based delays on emulators.

Add a kconfig style configuration program instead of requiring users
to modify config.h.

Support usb booting?  Support usb mice?

Add a graphical boot splash screen?

Possibly support sending debug information over EHCI debug port.
