UFO:Alien Invasion Code

* crushed png files

* Reduced filesizes of the tex_lights texture folder by compressing/optimizing the files with pngout

* Optimizations and lighting tweaks for alien base

* WIP alien base and a new set of general use lights

* new alienbase textures (gpl 2 or later by Nate Wright)

* Adjustments to tex_material/metal012 and 013

* GPL'd tex_material/metal001

* Normalmaps for some of my textures that were missing them.

* Some new textures for an electrical box

* Some new/updated textures