Performance Optimizations / Fixes

v 1.05

I've implemented some performance optimizations which should reduce the game's overall GPU usage.

Plus a new "Lighting" graphics option, when set to "LOW" should reduce GPU usage further without impacting the overall image quality too much.

Finally, fixed a bug in the main menu where you could enter a *FORBIDDEN FIRST PERSON ZONE* or, in other words, the empty test area that lives behind the main menu.

Let me know if you have any issues!