update misc notices

Also, pass empty_bv when bv_val is NULL.

Update 'hints' reference to point to FAQ.

Update lutil.h copyright.
CHANGES is a release engineering document.  Not maintained in HEAD.

Moved -u (udp) to -c (connectionless).  Connectionless is depreciated
and undocumented.
Added tests for set{,e}{u,g}id to configure.  Use existance of
setuid/setgid to enable feature.  Use seteuid/setegid only if
they exist.
Fixed minor minor leak of username/groupname if specificied
more than once.  (This should actually be an error)

of a busy wait and allow the pthread_yield within the loop to be
removed.  This was the only pthread_yield which was necessary
when usng non-preemptive threads.  As such, the configure.in
sched_yield/pthread_yield missing error can be removed from
configure.in.  If explicit yield function is missing, just provide
a no-op replacement.
Moved declaration of various slapd globals from main.c to init.c
so they can be shared with ldbm tools.