Copy and build daemon.c in whatever directories need it, instead of building it

Copy and build daemon.c in whatever directories need it, instead of building it
into the krb5 library.

* aclocal.m4 (KRB5_AC_NEED_DAEMON): New macro.
* appl/bsd/configure.in, kadmin/configure.in, kdc/configure.in,
krb524/configure.in, slave/configure.in: Use it.  Don't directly check if
prototype for daemon() is needed.
* kadmin/server/Makefile.in (OBJS), kadmin/v5passwdd/Makefile.in (SERV_OBJS),
kdc/Makefile.in (OBJS, fakeka), krb524/Makefile.in (SERVER_OBJS),
slave/Makefile.in (SERVEROBJS): Use LIBOBJS.
* config/post.in (daemon.c): New rule for copying daemon.c locally
from lib/krb5/posix.

ticket: 1791

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@15801 dc483132-0cff-0310-8789-dd5450dbe970