Julia 0.3 release blog post

Seems like a good idea to have this on the web too? Elliot's text from the email.

@staticfloat @StefanKarpinski
Not sure how I feel about that. It feels slightly too pandering, although I'm generally in favor of that kind of thing. Yes, this will end up on HN, etc. but it's also just our release notes, which serves a fairly specific purpose.