PBR Sneak Preview, ioquake3 + PlayCanvas renderer

https://www.youtube.com/watch?v=LcDTannSTCc

Kicked rend2 out of ioquake3 since it looks ugly and it only supported undynamic 90s .shader-files and non-standard 3d formats. Was alot of work, but slowly the game starts to look really good and it becomes easy-to-mod (e.g. using the GLTF standard now and it has lots of exporters and implementations, like for Blender3D). Everything is highly dynamic and most settings can be simply edited by writing some JavaScript in F12 DevTools.

There is still some work to do, e.g. currently it only supports my mp_toujane bsp map clone (probably going to fix today).

Random todo list:

- nice water shader, like https://playcanv.as/p/44MRmJRU/
- more animations for the maila model, like crouch-standby, crouch-left, crouch-back, jump-crouch, aim, aim-shoot etc. (learning blender for that...)
- proper fps weapon models with shoot/reload/whatever animations
- spawning some nice effects/particles for rocket-explosions and bullet-hits-wall, bullet-hits-water or bullet-hits-sand

Any ideas are welcome

Good job man, you're the best :)