Release v0.10.0

This is the announcement for v0.10.0. The [blog post is here](https://raw.github.com/elixir-lang/elixir-lang.github.com/0436224c048ee9ae4a0d99e342c1c6177e8bcd6e/_posts/2013-07-13-elixir-v0-10-0-released.markdown).

Feedback is appreciated. Is there anything important I left out?

/cc @alco @yrashk @ericmj