Updated the game to version 0.2.4

This update improves the general atmosphere across most of the game, and is the first in a series of planned improvements to the demo.

-Big light changes, a few areas completely re-done.

-Includes some new props for more varied lighting fixtures.

-New audio system added to some areas.

-Fixed a light that was only visible with lumen off.

-Minor changes to the sounds the first monster makes when spawning.

-Tweaked LOD settings on some props.