DIP80: phobos additions

[Ilya Yaroshenko via Digitalmars-d]

> Ilya, I'm very interested in discussing this further with you. 
> I have a reasonable idea and implementation of how I would want 
> the generic n-dimensional types in D to work, but you seem to 
> have more experience with BLAS and LAPACK than me* and of 
> course interfacing with them is critical.
>
> *I rarely interact with them directly.

I have created Phobos PR. Now we can discuss it at GitHub.
https://github.com/D-Programming-Language/phobos/pull/3397