Finish off Acceptable Licensing header

* OSI Code licensing
* Default MIT licensing in the presence of CC
* No derivatives aren't allowed
* Unlicensing isn't allowed

Closes #56 and Closes #116
I'm uncomfortable about this line. I agree with the sentiment that if no license is documented in either the script or its description, then the default license should normally be assumed (although this is already covered by the Default License section).  However, I don't think that this necessarily holds good in the case of a license dispute.  It may be that the script is a fork of one that originally had different a license, which has been stripped off, and this is the source of the dispute.  Using "resolution" in this way also implies the dispute has been resolved.

How about 
```markdown
* In the case of any code licensing dispute that requires resolution, if there is no evidence of a license being declared or documented for the original code, the [Default Code License](#default-code-licensing) shall be assumed.
```