Update copyright dates not handled by scripts/update-copyrights [committed]

[Torvald Riegel]

On Mon, 2017-01-02 at 17:19 +0000, Joseph Myers wrote:
> If the GCS were then changed along the lines I propose above, we'd still 
> need to establish appropriate conventions for commit message contents - 
> that is, that any nontrivial change should include a description in the 
> commit message along the lines of what goes in the mailing list posting of 
> the patch.  But we can of course establish such a rule for meaningful 
> commit messages independently of a change to the GCS.

I think we should do the latter (though I had assumed we already do
require that?)