framebuffer driver, etc. work on FreeBSD/amd64.
A significant amount of improvements were done by jkim@ during the recent
months to make vesa(4) work better, over the initial code import. This
work is based on OpenBSD's x86emu implementation and contributed by
paradox <ddkprog yahoo com> and swell.k at gmail com.
Hopefully I have stolen all their work to 8-STABLE :)
All bugs in this commit are mine, as usual.
