Make after-save-hook local.

Eclim spam in the modeline just because I have eclim installed is
annoying.  Can fix this by making the after-save-hook local to buffers
where eclim is activated.
Minor refactoring.

- There's not point in setting a value to its default.  In any event, we
  should probably not just setq variables like this because it affects
  the global session.  We should instead use global variables.

- The if-progn idiom is so common that someone made a macro for it a
  long time ago.  It's also good style to use WHEN/UNLESS if there's no
  ELSE clause.

- We should be consistent when we retrieve the function to add to a
  hook.  While #'function is technically more correct, nobody bothers
  using this form, so we'll favor the other one.