std.benchmark redux

[Andrei Alexandrescu]

I recall we have nothing in the review queue for the time being, is that 
correct?

If that's the case, allow me to tender std.benchmark again for inclusion 
into Phobos. I reworked the benchmarking framework for backward 
compatibility, flexibility, and convenience.

Code: https://github.com/D-Programming-Language/phobos/pull/794

Dox: http://dlang.org/phobos-prerelease/std_benchmark.html

There are a few enhancement possibilities (such as tracking system/user 
time separately etc), but there is value in keeping things simple and 
convenient. Right now it really takes only one line of code and 
observing a simple naming convention to hook a module into the 
benchmarking framework.

Looking for a review manager!


Thanks,

Andrei