Improvements to contrib/julia-mode.el (Emacs mode)

Add functions to execute Julia code in Terminal.app on Mac OS X.

Improve font lock.

Function julia-documentation based on ESS’s Julia mode plus fix.

Set comment-add to 1.

Add key bindings.

Add logic for auto-mode-alist.
Since this is OS X specific, have you considered releasing it as a separate elisp package? That way you can provide a tailored OS X experience without making julia-mode less generic.