Started implementing in-game commands, expanded test world.

Finally got create-player working.

Created an ATL-mode for Emacs and expanded the test world.

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.

Enabled recursive loading of ATL files, implemented option command behaviour. ...

The latter caused many headaches, and great joy in its completion :D

Integrated interpreter.lisp with atlantis.lisp, various bug fixes.