Move UCB-licensed code from 4-clause to 3-clause licence.

Patches provided by Joel Baker in PR 22280, verified by myself.

put utmpx/wtmpx routines to separate files, so that programs overriding the
utmp/wtmp routines could still be linked static
fixes e.g. static build of ftpd

add utmpx/wtmpx processing routines.

- __RCSID() police.
- ANSIfy.
- Miscellaneous style changes.
- Shutup lint(1) in one or two cases.

back out the #ifdef _DIAGNOSTIC argument checks; too many people complained.
_DIAGASSERT() is still retained.

* use _DIAGASSERT() to check pointer arguments against NULL and file
descriptors against -1 (as appropriate).
* add actual checks which to detect stuff that would trigger_DIAGASSERT(),
and attemp

* use _DIAGASSERT() to check pointer arguments against NULL and file
descriptors against -1 (as appropriate).
* add actual checks which to detect stuff that would trigger_DIAGASSERT(),
and attempt to return a sane error condition.
* knf some code
* remove some `register' decls.

the first two items result in the addition of code similar to the
following in various functions:

_DIAGASSERT(path != NULL)
#ifdef _DIAGNOSTIC
if (path == NULL) {
errno = EFAULT;
return (-1);
}
#endif

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Delint

Need <time.h> for time() prototype.

- RCSID police
- Add ttymsg.3

Minor reorganization of libutil, including the addition of passward
locking and editing functions.
From Greg Hudson <ghudson@MIT.EDU>

Prototypes (PR#1100).

minor cleanup; kill unnecessary casts

Add RCS identifiers.

initial import of 386bsd-0.1 sources