4digits: A guess-the-number game, aka Bulls and Cows

Version 0.8 (11/22/2007):
    GUI version:
    * High score recording and viewing.
    * A hint table, which can be used to mark possibilites.
    * Auto filling hint table.
    * Desktop entry file.
    * An install script in python copied from Comix.
    * Detailed documentation.
    * Visual improvements.

    Text version:
    * Correct duplicate input handling.

Version 0.4 (03/22/2007):
    * PyGTK GUI, just playable.
    * HTML documentation.

Version 0.3 (11/18/2006):
    * Improved user input handling.
    * Command line switches.
    * Improve high score recording.
    * Fixed a "won't-quit" bug.
    * Remove online help during game.

Version 0.2 (08/14/2006):
    * Even improved user input handling.
    * Manual page.
    * Timing and high score recording.

Version 0.1 (12/2005):
    * Improved random number generation.
    * Input error handling.
    * Online help during game.
    * Much code rewritting.
    * Makefile.

Version 0.0.1 (2004):
    * First public release, merely playable.
