UFO:Alien Invasion Code

* Advanced repack of tex_alienb/ by pngout

* Reduced filesize of the tex_alienb textures folder by compressing/optimizing the .png files with pngout

* Texture/map tweaks for alien base

* Small fixes for alien base floor textures

* Adding crate textures and prefabs to be used in alien base (also a couple updates on .map and .mat)

* Hi-res textures for alien base WIP with new map and mat files