smb.conf.5: add clarification how configuration changes reflected by Samba

smb.conf.5: add clarification how configuration changes reflected by Samba

Users of Linux distributions know to read smb.conf(5) manual page but
apparently not many of them read smbd(8) and winbindd(8) to understand
how changes to smb.conf file are reflected in the running processes.

Add a small section that makes it clear where to find relevant
information. Also correct the information in smbd, nmbd, and winbindd
manual pages.

The interval at which smbd does check for smb.conf changes was increased
from 60 seconds to 180 seconds in 1999 with commit 3db52feb1f3b.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=14538

Signed-off-by: Alexander Bokovoy <ab@samba.org>
Reviewed-by: Isaac Boukris <iboukris@samba.org>
Autobuild-User(master): Alexander Bokovoy <ab@samba.org>
Autobuild-Date(master): Tue Oct 20 08:50:13 UTC 2020 on sn-devel-184

(cherry picked from commit e32846f0692df44b4ee929c5ed6ba1de88ec4bd2)