Add creative commons license info for CC0

[eaquigley]

---

Author Name: Gustavo Durand (@scolapasta)
Original Redmine Issue: 1828, https://redmine.hmdc.harvard.edu/issues/1828
Original Date: 2012-02-16

---

We need to evaluate with Merce what this entails; how it interacts with Terms of Use, etc.

[sekmiller]

Basic functionality completed

[kcondon]

This is effectively a dupe of the other TOU ticket, closing.