- The package's real name is "z.lua", not "zlua".

  Using this name for now, until we can evaluate
  whether such a name will play nice with pkgsrc.

- There's also an images/ dir referenced by README.md, which
  we may want to include.

- See if there's a way to replace the `lua' statement in the eval
  in MESSAGE with the selected version of lua (eg, lua52 or lua53).
