libedit: add H_SAVE_FP which saves history to a file pointer.

H_SAVE_FP is similar to H_SAVE but operates on a FILE* instead of a filename.
This is useful when operating in capability mode.

Reviewed by:	christos@NetBSD.org, pfg
Make ofwfb not be painfully slow. This reduces the time for a verbose boot
on my G4 iBook by more than half. Still 10% slower than syscons, but that's
much better than a factor of 2.

The slowness had to do with pathological write performance on 8-bit
framebuffers, which are almost universally used on Open Firmware systems.
Writing 1 byte at a time, potentially nonconsecutively, resulted in many
extra PCI write cycles. This patch, in the common case where it's writing
one or several characters in an 8x8 font, gangs the writes together into
a set of 32-bit writes. This is a port of r143830 to vt(4).

The EFI framebuffer is also extremely slow, probably for the same reason,
and the same patch will likely help there.
look(1): add compability with other implementations.

On other implementations 'look -a' uses an alternate dictionary.  Since we don't
have one, just ignore it.
mesg: remove advertising clause

The University of California board of trustees has given permission to remove
the advertising clause of all software attributed to it.
Port over mmap routine from syscons. This lets X11 work on PowerPC with vt.
The last obstacle to switching PowerPC entirely to vt is that the Playstation 3
framebuffer driver needs to be ported over. This only applies for powerpc64,
however.
Use vt(4) by default on 32-bit PowerPC now that it is fully functional and
fast. 64-bit PowerPC will follow along once the PS3 framebuffer driver is
adapted.