Integrate Rise of Rome (AoK prequel)

[FolkertVanVerseveld]

@TheJJ asked me back in january to join forces to speed up developing
OpenAge. Unfortunately, life had other plans for me so hence the 3
months delay.

I think it would be a nice thing to have to be able to provide support
for the prequels of AoE II as well. In my opinion, the original AoE is
very limited due to lots of boring micromanagement. I would like to help
to integrate the expansion to AoE: Rise of Rome.

Let me know what you guys think or what you need help with the most so
we can improve OpenAge together and maybe integrate the prequels in the
future :D

Some things I've come up with:

To integrate the prequels OpenAge either needs to provide multiple setup
options in the configuration scripts for the specified build target
(e.g. --game=[AoK|RoR|AoC]) or the game engine needs to be upgraded to
support different genie game engines on-the-fly.

Some of the issues that need to be resolved:

• The Genie game engine in all AoE II games are very different from the
  original game engine used in AoE I and RoR (especially with
  path-finding).
• Verify whether the file format of original game assets in AoE II are
  compatible with the original game assets (otherwise, we need to
  upgrade the assets converter to also support RoR).

Related:

• AOE I support: Integrate Age of Empires I #808
• SWGB support: Star Wars Galactic battlegrounds support #421

[TheJJ]

The openage engine shall support all the features of all games. The game setup and configuration is done 100% in nyan (https://github.com/SFTtech/nyan, #28).

So the only thing missing (apart from engine features that are crappy even for aoe2) is to add convert support for the other games. Namely we need to be able to create data packs from all those games #632. The asset pack contains all the asset (sounds, sprites) and gamedata (in nyan). The engine then loads the pack and runs the simulation (#740).

So I'd say the first thing is implementing #632 and adding support for other games in the converter.