Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

- Add support for ASCII art splash screens in TheDraw format

PR: kern/143370
Submitted by: Antony Mawer <antony@mawer.org>
Reviewed by: gjb (doc)
Reviewed by: des (style)
Approved by: ed
MFC after: 1 month

$Id$ -> $FreeBSD$

PCX loader for pseudo-device splash.

Add splash screen module. This version has rather limited
capabilities, but should be a good start... Well, sort of.

It can handle W*ndows 256 color BMP file. (Other color depth probably
won't work.) The size of the image must be 320x200 or less. *sigh*