Some refactoring in world/game-object, expanded commandline parameter parsing.

Refactored game command system, added 'player' command. ...

Version 0.1 is now ready - ATL files are parsed properly, the world
and the player are created, and the player can move around inside
the world. The first stage of a long journey is hereby completed!
:-)

Saved a lot of code by writing build-symbol, started on client module.

Enabled Lisp extension files to be loaded from ATL source file. ...

Also added option to show license to interactive start menu, and
various small bug fixes/additions.

Added races and character classes, wrote safe-guard against circular imports.

Expanded interpreter, started on world.