valid_link - controls the use of the link efun

int valid_link( string from, string to );

The driver calls valid_link(from, to) in the master object from inside the
link(from, to) efunction.  If valid_link() returns 0, then the link()
will fail.  If valid_link() returns 1, then the link will succeed if
rename() would succeed if called with the same arguments.

See also:
 link

 Tim Hollebeek  Beek@ZorkMUD, Lima Bean, IdeaExchange, and elsewhere
