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.
Well, unless we implement a full Julia parser in emacs regexps, it will always be possible to come up with counterexamples. I have been using my regexps for a few months and never had any problem.