Fixing bugs:
cardwords_gtkclient:

* Show the meaning of wildcards during move creation also on the card-table.


Adding features:

cardwords_server:
* Extend end of game: assign final points, reveal opponents' cards.

cardwords_textclient:
* Write it.

server and clients:
* Build or adapt CGTP (Crossword Game Transfer Protocol).
  The Protocol clients and server use is currently not documented and is
  messy. I'm currently learning about how to write such a protocol that
  could probably lead to an rfc; but I would gladly adopt such a protocol if
  someone else writes it and it could be used for cardwords.


Cleaning source code:

* Fix all FIXMEs.

* Change c-style (casts) to static_cast<>() and
  dynamic_cast<>() where appropriate.

* Change INT_MIN etc to numeric_limits<int>::min() etc when stdc++ supports
  it.

* Declare the copy constructors of all CardWords_Gtk* classes private.
  This is to discover use of the copy constructor at compile time.
  Use of the copy constructor for these classes is usually a bug that
  would lead to double deletion and thus segfaults.

* Header files needing only pointers to custom classes foo or references
  should not include the header file where this class is defined. Instead,
  declare class foo in the header file and include the header file of the
  referenced class only in the implementation file.

* Outline unnecessary inlined methods.