(vers): Don't report KSU distribution (1.04 in all known versions),

(vers): Don't report KSU distribution (1.04 in all known versions),
Chainsaw version (4.00 since Empire 2, ca. 1995) and Wolfpack version
(used to be the version number after the first dot).
(KSU_DIST, CHAINSAW_DIST, WOLFPACK_DIST): Unused, remove.

(version): New.
(EMP_VERS_MAJOR, EMP_VERS_MINOR, EMP_VERS_PATCH): Remove.  Users
changed to use version[] instead.  version[] is slightly easier to
initialize from configure.ac.
(check-version): No longer needed, remove.

(legal): New.
(vers, main): Show it.