mozjpeg 1.0.1 (new formula)

Add mozjpeg, a JPEG encoder created by Mozilla that focuses on efficient encoding.

[More information is available here](https://blog.mozilla.org/research/2014/03/05/introducing-the-mozjpeg-project/).
Can this test be modified to do something more substantial then e.g. `--version` or `--help`? See `tinyxml2.rb` for an example of a formula with a good test. Thanks!