Add a license

[Aaron L]

Can we get the license for the unix portion then? The original library was MIT, would be grateful if this ended up MIT as well.

[onlyjob]

It is important to document all licenses (and copyrights) as well at to commit full text of the license.

[onlyjob]

Blake, it would be great if you could add your own copyright statement and license grant. Thank you.

[Euan Kemp]

ping @bgentry

[Blake Gentry]

added an MIT license for non-Windows portions, sorry this sat for so long.

[Euan Kemp]

Thanks!