No functional changes.  Rewrite comments, use tabs consistantly, reorder
some of the functions so that similar things are grouped together.
Use panic rather than printf to "handle" an arm26 address exception
(should never happen on arm32).  Pass the right arguments to panic for
the reset exception (which also should never happen).
Replace the userspace atpic stub with a more functional vmm.ko model.

New ioctls VM_ISA_ASSERT_IRQ, VM_ISA_DEASSERT_IRQ and VM_ISA_PULSE_IRQ
can be used to manipulate the pic, and optionally the ioapic, pin state.

Reviewed by:	jhb, neel
Approved by:	neel (co-mentor)
Remove clause 3 (advertising clause), per regent's letter.
Remove clause 3 (the advertising clause), per the regent's letter.