Started on creator.lisp, the ATL code generator, and implemented spreadsheet parsing. ...

Very proud of myself - this commit transforms a spreadsheet into code in under
40 lines of Lisp, and I wrote that in two hours, starting at midnight :D

Implemented about/talk/clear commands. ...

Also expanded the test world. Plus, I have now broken the 1000 line barrier! :-)

Implemented item pickup/dropping/equipping. ...

Also expanded the test world and some other adjustments.

Some refactoring and bug fixing (introduced debugging print function).

Added single-player mode, enabled saving/loading of a game. ...

Also related code cleanup.

First commit on the single-player branch. ...

Networking is proving to be a major challenge, so I'm bypassing it for now...
Refactored the start menu.