Further Material Improvements

There is now an additional metallic material used for the antennas. The newly-created spaceship can be aligned to the world, view or 3D cursor. The unlit part of the hull-lights material is now a better match for the rest of the hull. The grunge factor now reduces the glossiness of hull materials, and also affects the hull lights. The redo panel now lets you expand/collapse the details of the hull materials. There is now a common colour-scheme node group, so you can come back and edit the hull colours in one central place after the redo panel has gone.