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
> (although this is already covered by the Default License section)

Legal redundancy... in all legalese this is present. :)

>  It may be that the script is a fork of one that originally had different a license, which has been stripped off

That would make it declared and documented thus the sentence holds true and the default license wouldn't apply unless it was a Content only license.