toString refactor in druntime

[Kagamin via Digitalmars-d]

On Thursday, 30 October 2014 at 16:03:01 UTC, Steven 
Schveighoffer wrote:
> Keep in mind, sink delegate is not a singly implemented 
> function, it's implemented wherever the output is done. So it's 
> a lot of boilerplate to copy around.

Only 2 lines.

> This way, when write finds it runs out of space, first thing it 
> does is sink the buff, then starts sinking the rest. In fact, 
> you can just keep using buff once you sink it, to avoid future 
> "extra calls" to sink.

I tried to make the code minimalistic. Thought that can give 
advantages.