unicorn 3.2.1 - parser improvements for Rainbows!

There are numerous improvements in the HTTP parser for
Rainbows!, none of which affect Unicorn-only users.

The kgio dependency is incremented to 2.1: this should avoid
ENOSYS errors for folks building binaries on newer Linux
kernels and then deploying to older ones.

There are also minor documentation improvements, the website
is now JavaScript-free!

(Ignore the 3.2.0 release, I fat-fingered some packaging things)