[Babel-users] v4-over-v6 implementation

[Théophile Bastian]

Dear all,

I have re-implemented in a cleaner way v4-over-v6, and I think that my
current version is ready for merge, or decently close to it.

You can find this implementation here:

   https://github.com/tobast/babeld/tree/tobast/v6tethered-reimplem

aka. branch `v6tethered-reimplem` on https://github.com/tobast/babeld/

Any test or feedback is welcome!

-- 
Théophile Bastian