How to package executables

[Karl Berry]

    - put spix directory containing __init__.py and __main__.py into

Names like __*__.py with no package name are inherently ambiguous in the
TeX world.

Maybe that doesn't matter in this particular case, since there's
presumably no reason to ever look up __main__.py with kpsewhich. On the
other hand, this is breaking new ground -- there are no __*__.py files
in TL now. I am automatically leery. 

    since there is already a bin/spix that used dirname $0 ../

Well, good. I await its next CTAN upload :). --thanks, karl.