uname.2: deweirdify

uname.2: deweirdify

The NOTES were not only weirdly reductionist, but also highly
opinionated in the wrong direction.

Yes, it's a syscall in SysIII; not in 4.4BSD.
Well, in general, it exists in 4.4BSD for obvious conformace reasons.
No, it doesn't "know" (and if it does, that's not relevant),
historically and practically this is the broad CPU/machine type
(compare uname -p on SysVr4 (=> SunOS 5 => NetBSD),
 which is the actual CPU model (usually)).
Everywhere, ex. def., the nodename is what the BSD calls the hostname.
"No standard" also speaks of sethostname(), so.
Historical precedent (i.e. all implementations, save *maybe* for weirdo
XENIX, who cares about weirdo XENIX) defines the hostname to be uname -n
(indeed, SVr3 uname -S sets /both/ nodename /and/ sysname!
 that's not relevant here;
 SunOS gets it from the network (unless configured manually)).
Someone clearly cited SysVr4's "Internet hostnames" comment w/o credit;
fix that.
8-byte truncation is really quite secondary here (indeed, that's what
 SysVr4 does for pre-SysVr4 uname() callers that haven't been rebuilt.
 you will never encounter it).
The hostname is not meaningless, obviously??
Also fix machine to say "hardware type", like the standard;
"hardware identifier" would be hostid. I wrote six seething pages about
hostid, and machine is /not/ hostid.

Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>