chez-scheme: 9.5-20171109 -> 9.5.1

  - Add a new postInstall hook that installs Chez's kernel.o file into
the library directory. This library /should/ be installed by Chez, but
isn't, and it's the only way to properly embed Chez in your applications
or write your own shell/bootfile harness directly.

  - Fixes the version number for Nix to properly reflect the one Chez
shows the user.

  - Loose odds and ends (fix homepage URL, tidy up comments)

Signed-off-by: Austin Seipp <aseipp@pobox.com>