Update Pelican to 3.2

Pelican, the static website generator I use to create this site,
was upgrade to 3.2 on 2013-04-24[0]. This update merely adds the
suggested `from __future__ import unicode_literals` to the top
of the Pelican settings file and updates the requirements file
to reflect the updated Pelican packages (as well as its updated
dependencies).

[0]: http://blog.getpelican.com/pelican-3.2-released.html