interactive - detects whether or not a given object is an interactive

int interactive( object ob );

Return non-zero if 'ob' is an interactive player. 0 will be returned
if he is link dead.

See also:
 query_ip_number,
 query_ip_name,
 enable_commands

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