bin/166660: new stdbuf utility

[Jeremie Le Hen]

Hi hackers,

I've posted a PR bin/166660 this morning:
    [patch] New util/shlib to change per-fd default stdio buffering mode

For some unknown reason, "[libc]" has been prepended to the subject, but
this patch __DOES NOT touch libc__ (except a one-line addition in a
manpage).

This is aboslutely non-intrusive and can be easily MFC'd to RELENG_9,
RELENG_8 and even RELENG_7 if it hasn't reach itf end-of-life.

In brief, this is a new tool that allow to control default fd stdio
buffering mode.  The feature exists in Linux and its command-line
interface is BSD-compatible, so I used the same name and the same
interface for obvious compatibility reasons.

As you can guess, I'm looking for someone willing to test (though I've
already tested it and the code is pretty straightforward) and commit it.

You will find additional information in the PR.

Thanks.
-- 
Jeremie Le Hen

Men are born free and equal.  Later on, they're on their own.
				Jean Yanne