Firstly, compile d2x.

Then stick it in a directory with these files from a Descent 2
Registered Installation (the version _does not_ matter). Shareware may
work if you hack at the shareware build system, but I haven't even
attempted it.

I needed these files: (in addition to the d2x binary)
alien1.pig
alien2.pig
descent2.ham
descent2.hog
descent2.s11
descent2.s22
fire.pig
groupa.pig
ice.pig
water.pig

Note the filenames must be in _lower case_. It's important.
