OpenMW files support

[johannesrld]

Is your feature request related to a problem? Please describe. When installing mods made specifically for openmw, if its using openmw specific features (e.g omwgame, omwaddon, openmw animation support) MO2 throws up an error stating that the mod dosent have any valid files

Describe the solution you'd like support .omwaddon and .omwgame files

Describe alternatives you've considered potentially treat openMW as a separate game

[AnyOldName3]

So the gist of the situation here is that it would break the vanilla engine if we tried feeding it .omwgames/.omwaddons/.omwscriptses (that's a gross pluralisation if I've ever seen one). There's also not any good reason for OpenMW to be a separate game other than this, but it would make things like downloading Morrowind mods a mess (as it wouldn't know which instance to associate them with). We need to design a system that keeps the files active when OpenMW or the export plugin is run, but temporarily disables them when Morrowind.exe is run, or something along those lines.

The specific no-valid-files warning can be eliminated pretty quickly by adding the necessary file extensions and directory names to the list of valid files. I think that's global instead of per-game, but might have been moved with the basic_games support. If it's global, then there's no good reason not to add OpenMW-specific files to it.

Other OpenMW-related things include:

• Keeping the groundcover list separate from the main content list. Maybe this could be done in a flexible way that can be hooked up to MGE XE's distant land generator, too, so you can pick which files it sees via MO2.
• Activatable BSAs as a Game Feature as they're super simple to register for Morrowind and then I can make the OpenMW export plugin register them for OpenMW, too.