RE: Timeout parameters

Hi, all.

# This is a supplement of my current patches.

> From: Nagaura, Ryohei [mailto:nagaura.ryohei@jp.fujitsu.com]
> > In TCP_backend patch:
> > I think this is not mentioning backend. Why don't you copy'n paste
> > then modify the description of tcp_keepalives_idle? Perhaps it needs
> a
> > similar caveat related to Windows.
I modified documentation with referring ones of tcp_keepalives_*.

Also, Note that:
1) I added <note> about windows OS and some linux kernels.
2) Documentations about TCP_USER_TIMEOUT is made citing description of [1].
    # The client-side patch does as well.
3) Same as keepalives*, I used both "0" and zero.
I can't recognize why to use both of them.
Is there anyone who know it?

[1] https://tools.ietf.org/html/rfc5482
Best regards,
---------------------
Ryohei Nagaura