Permitting certificate for data when rights are unclear

**For discussion, not ready for merge.**

Bit of background at http://lists.okfn.org/pipermail/okfn-discuss/2013-July/009455.html

This PR enables open data publishers who do not have clear rights to publish the data they are publishing to get an Open Data Certificate. The question **Do you have the rights to publish this data as open data?** now has four possible answers:

  * yes, you have the rights to publish this data as open data
  * no, you don't have the rights to publish this data as open data
  * you're not sure if you have the rights to publish this data as open data
  * the rights in this data are complicated or unclear

To get a **Raw** certificate, you must not answer 'no' to this question. You can get a **Raw** certificate if you answer that the rights are complicated or unclear.

To get a **Pilot** certificate, if you have answered that the rights are complicated or unclear then you must answer the question **Where do you detail the risks people might encounter if they use this data?** which has the help text:

> It can be risky for people to use data without a clear legal right to do so. Give a URL for a page that describes the risk of using this data.

To get a **Standard** certificate (or higher), you must answer that you have the rights to publish the data as open data. You cannot get a **Standard** certificate if your right to publish is complicated or unclear.

I'm interested in any thoughts about wording of these questions, particularly from @konklone and @CountCulture.