Various fixes to UV2 unwrapping and the GPU lightmapper. Listed here for
context in case of git blame/bisect:
* Fix UV2 unwrapping on import, also cleaned up the unwrap cache code.
* Fix saving of RGBA images in EXR format.
* Fixes to the GPU lightmapper:
- Added padding between atlas elements, avoids bleeding.
- Remove old SDF generation code.
- Fix baked attenuation for Omni/Spot lights.
- Fix baking of material properties onto UV2 (wireframe was
wrongly used before).
- Disable statically baked lights for objects that have a
lightmap texture to avoid applying the same light twice.
- Fix lightmap pairing in RendererSceneCull.
- Fix UV2 array generated from `RenderingServer::mesh_surface_get_arrays()`.
- Port autoexposure fix for OIDN from 3.x.
- Save debug textures as EXR when using floating point format.
Upgrade OIDN to 1.1.0, the latest stable version that doesn't need
the ISPC compiler.
Documented the changes made during the removal of TBB and added a patch
file for them.
-Added LocalVector (needed it)
-Added stb_rect_pack (It's pretty cool, we could probably use it for other stuff too)
-Fixes and changes all around the place
-Added library for 128 bits fixed point (required for Delaunay3D)
