eval-after-load & ensure program exists for ispell

  Suggested by Ircg [1], taken from a patch to technomancy's starter
  kit.

  Might want to add a direct call to `turn-on-flyspell' after the
  add-hook inside the `when' to address Ircg's problem in issue 63.

[1]  https://github.com/eschulte/emacs24-starter-kit/issues/63