This function is used to subscribe to an existing publication, 
      and to specify the local WebDAV owner (for replicated WebDAV content).  
      Before making a subscription the repl_server() must be called in order 
      to define the publisher server.  After making a subscription it becomes 
      off-line until it syncronized from scheduled task or with repl_sync() function.  
      Also the initial data of the subscription will be not loaded until 
      repl_init_copy() called or initial image loaded.