Modifies vox armalis and vox items and sprites, adds species-specific sprite sheet system.

You can now define an associative list in each species datum that contains icon files for given categories. Defining these list entries will mean the mob will only display on-mob icons for things defined in the specified file. Ie. If you put on item X as a human, you will display item X from the base uniforms.dmi file. If you are a Tajaran with a "uniform" species sprite_sheets entry defined, and you have a corresponding icon for item X, you will render from your species-specific file. If you are a vox with "uniform" defined but no sprite, you won't render anything.