Move daemon.c into a new library of utility routines for linking our programs

Move daemon.c into a new library of utility routines for linking our programs
against but which we don't want to install as a separate library.

Change Kerberos and application servers to link against the library if they
might need the replacement daemon() function.

Add a dummy file to the library in case daemon() is not needed, so we don't
have an empty library, which we may not handle properly.

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@16118 dc483132-0cff-0310-8789-dd5450dbe970