To make a ferry-line.
=====================

Making a ferry-line isnt that hard, all you need is:
* one control room.
* one lighthouse or other way to call the ferrys in each harbour.
* at least one ferry.

Control room
------------
To make a control room, inherit /std/special/ferry/ferry_control
and configure it.

add_place(filename, place, X, Y)
  Adds places to where the ferrys can go. filename is the filename
  where the harbour is and place is the name of the harbour.
  X and Y are coordinates on a though map. The time to travel between
  two harbours is the euclidic distance between those places on this 
  though map.
  The harbours are normal rooms.

add_ferry(filename)
  Adds ferrys to the ferry-line. A ferry can only belong to one line.
  How the ferrys are made is explained below.

set_start(filename)
  Sets in which room all the ferrys of one line starts. This should
  be one of the harbours added by add_place.

To call ferrys
--------------
  In every harbour there must be a way to signal a ferry. This is done
  by calling the function call_ferry in the control room and as argument 
  having the filename to the harbour.

  CONTROLER->call_ferry(HARBOUR);

Ferry
-----
  To make a ferry, you need both the inside of a ferry and a facade that 
  is seen from the harbour.

 Inside:
  The inside of the ferry should inherit /std/special/ferry/ferry.
  That file is based on /std/room, so you can use all functions
  in it. The things that are special to ferrys are that there is already a 
  sign defined, so it is good to mention it in the set_long. The special 
  functions for configuring a ferry are:

  set_ferryman_name(name)
    A lot of messages are said by somone. The name of this person is 
    defined here. If this isnt defined, the person will be called The ferryman.

  set_boat_type(type);
    This is what the people at the shore sees arriving and leaving. Suitable
    types are boat, ferry, ship etc.

  set_facade(filename);
    This tells the boat where it can find the facade that should be put in 
    the harbour.

 Facade:
  The facade has to inherit /std/special/ferry/ferry_outer. It is based on
  /std/stationary and can be set up accordingly. No special configuration is
  needed.
