Evaluate possibility to integrate WFG's Rome at War artwork

[roybaer]

Given that Rome at War, the older project by the 0 A.D. developers, is an Age of Empires II: The Conquerors Mod Pack, a cooperation and clarification of the licensing terms would make a lot of sense. This mod pack could then provide most of the buildings, while pull request #19 would provide the terrain textures.

[TheJJ]

good idea :) once we actually need assets and the engine api is "stable enough" we should look into this.