Privacy policy

- Since we're collecting email addresses, we'll need one of these (Tim,
feel free to rewrite it, you're better at this stuff than I am)
- I took this opportunity to make use of my Privacy Deed project, I hope
you all agree it's awesome

New files:
- A whole bunch of privacy icons (all in the /privacyicons/ directory)
- privacy.php: A privacy policy
- privacydeed.css: CSS for the Privacy Deed