[phobos] Transferring Copyright to D Language Foundation

[Jonathan M. Wilbur via phobos]

I would like there to be a Punycode library in the D standard 
library. I tried to write one myself, but among the Wikipedia 
page and the RFC, I could not quite figure it out. I am sure that 
I could probably figure it out if I put the time and effort into 
it, but that seems unnecessary. I found a Punycode repository on 
GitHub that is written in D and looks perfectly fine.

Since I would like to submit pull requests to Phobos for other 
things, and since some of my code will need Punycode encoding and 
decoding, I wanted to get the owner of that repository to submit 
the pull request. Then, after std.punycode becomes a reality, 
then I can reliably submit my code.

The problem is that his code is copyrighted under his name using 
the MIT license, yet, according to the D Wiki, you must turn over 
the copyright to the D Language Foundation if you wish to submit 
to Phobos. I have been in contact with him via email and he is 
willing to forfeit the copyright to the D Language Foundation.

So my question is this: what is the best way--legally 
speaking--to go about submitting his punycode library to Phobos? 
How do I provide proof to the D Foundation that he has forfeit 
his copyright (if he can even do that)? After that, should I 
submit the pull request to Phobos (still giving him full credit), 
or do I need to have him submit the pull request?

P.S. Punycode is used in internationalizing domain names, which 
would have uses for std.uri or an std.dns (if such a thing comes 
to exist).