Update greek elite units

Dang, that was released a decade ago.

I believe that the Heliopolis was originally a regular unit you could make - If I recall, you had it instead of the Ballista. At some point it was moved to an advisor unit, and the Ballista was added in it's place.

Don't quote me on that, it was a long time ago, but htat's why the Heliopolis is shown to display gear in that old, old trailer but doesn't anymore.