[New Feature] Support MIX file map packs.

[CCHyper]

Description:

Red Alert 2 and Yuri's Revenge support map packs MIX files. These map packs contain a PKT file that defines the multiplayer maps to be added, and the map files themself.

Possible Implementation:

Implement the system exactly how it is in Red Alert 2 and Yuri's Revenge. Optionally, adding the ability to load extra graphic and audio files from this MIX file.

[E1Elite]

These mmx or yro like mix files if implemented should provide a sandbox environment that could include its own arts, sound, theme etc. INI files along with audio-visual content. Sandbox in the sense that these mix files are not considered as generic game addons like expandXX.mix, but are addons for the map files packaged along with it. This could provide a mini mod environment where the base game is locked for say online gaming like CnCNet.

[CCHyper]

@Bittah Are you able to produce a "mini mod" where this feature can be tested? A custom map, modified Art.ini and Rules.ini, and a new Voxel and HVA combo, all within a MIX file might be enough to test this.

[Metadorius]

IMO ideally the INI files should be loaded on top of the base INIs like the map rules are. This would be most convenient for the custom map authors I think.