Make gamedata fully optional and move it into separate project

[Xottab-DUTY]

To be fully compatible with the original engine, we should make all our gamedata improvements optional.

Then, we can create a new project on behalf of OpenXRay which delivers improvements and fixes to the original game, but is not limited to that only. In this new project we can implement new features that are not suitable for xray-16 (because it is a platform for modmakers, but not mod itself)

[Xottab-DUTY]

First step on this is to solve #473 and make all other shaders optional.

Scripts and configs are already optional.

[007exe]

However, for Linux, OpenGL shaders that are not available in the vanilla version remain mandatory. Perhaps you should add and download shaders from /usr/share/openxray/shaders for Linux along the standard paths?

[Xottab-DUTY]

@007exe, if we implement #258, then OpenGL shaders won't be a mandatory =)

Perhaps you should add and download shaders from /usr/share/openxray/shaders for Linux along the standard paths?

No, that's unnecessary and may be confusing. Standard gamedata/shaders/gl is enough.

[Xottab-DUTY]

#473 is done. Next step is #492.

[Xottab-DUTY]

All gamedata (except GLSL shaders) was removed. Next step is to restore it in the OpenXRay Plus project.
https://github.com/OpenXRay/plus

P.S. #492 is still to be implemented.

[Xottab-DUTY]

To close this issue we need to implement #258, while #492 is optional.