Vega Strike Code

Attention Windows users: Do NOT upgrade to this /data revision unless you know a way to compile the engine for windows with cubemaps enabled... --and if you do we'd like to hear about it. This commit commits cubemap versions of all the shader, plus new shaders and techniques (highend_flat, fireglass). It also contains updates to the Agricultural and Diplomatic centers, to use the new shaders, including fireglass, and adding ambient occlusion and shininess. The Mining Base is updated only insofar as its glass bubbles call for the fireglass shader.