[PATCH:xload] Integrate gettext support with autotools build system

[Mark Kettenis]

> From: Alan Coopersmith <alan.coopersmith at sun.com>
> Date: Fri, 15 Jan 2010 22:30:07 -0800
> 
> Mostly cribbed from prior work for libXpm

Ugh, ignore the message I just sent.  This diff obviously adds the
necessary autoconf magic.

(Did I ever rant on this list how I hate the way git encourages people
to split up diffs in pieces that are too small to be reviewed
seperately, especially when the pieces get reordered in mailqueues
along the way?)