[After fumbling around in the makefile forest for a while, Sigbjorn
enlightened me as to where one registers new hslib packages.  Golly,
never thought of looking over here.  I'd kinda expected that it would
be in the makeforest since makefiles seem to contain all (or almost
all) the information needed to install a package.  (Any chance this
stuff could be moved into the makeforest in the new library
infrastructure?)  It seems that'd be more effective since it'd be able
to benefit from all that good information that autoconf spent so long
figuring out about your X installation, your platform, your
internationalisation library, etc.]

Oh, yeah, the change... Added xlib to the package list.  Result looks
plausible.