build: Fix macro searching

The directory m4/ isn't checked into source control, so why are
we saying that there's additional macros there? With libtool gone,
it won't complain anymore.
build: Use AC_CONFIG_FILES
build: Update gettext infrastructure
Remove support for Xft

It's 2013. Pango is the modern toolkit for text drawing.
Remove psuedo-transparency

If we need this in the future we'll use proper compositing features
like an ARGB32 X window.
xtext: Remove overdraw
xtext: Remove double buffering code

GTK+ provides its own double buffering in the new paint model,
which we'll need to port to.
xtext: Remove some unused structure variables