std.simd module

[F i L]

Looks good to me so far ;-)


> First criticism I expect is for many to insist on a class-style 
> vector
> library, which I personally think has no place as a low level, 
> portable API.
> Everyone has a different idea of what the perfect vector lib 
> should look
> like, and it tends to change significantly with respect to its 
> application.

I think it would be useful, especially to newcomers who are 
unfamiliar with D's lib terrain, to have an officially supported 
"utils" library for these higher-level structures.

core // to the metal
std // low-level but useful
util // get the job done