0.9.0

• Change the OpenXR backend to use D3D11 mode. This mode is more compatible with third party OpenXR layers. The game rendering is still done in Vulkan, this is only the graphics API that OpenXR is using.
• Implement support for XR_VARJO_quad_views. This in conjunction of Quad-Views-Foveated OpenXR layer enables foveated rendering for openRBRVR when using OpenXR, resulting in a big performance improvement on most of the original format stages. Sadly, BTB stage rendering is CPU bound and the performance there is worse with quad view rendering so openRBRVR automatically disables the feature for BTB stages if it's in use. Also, some original stages are heavy on the CPU, like Verkiai. These stages run worse with quad view rendering, similarly to BTB stages. Using quadViewRendering = false in the corresponding gfx block in openRBRVR config it's possible to force normal stereo rendering for the problematic stages.
• The change of the OpenXR backend also enables support for OpenKneeboard. The version that will work with openRBRVR is not yet released, the support should land in OpenKneeboard 1.9.0. OpenKneeboard can then be used to bring desktop windows into the VR environment, like SimHub overlays.
• Implement support for OpenXR motion compensation layer (OXRMC), contributed by @mattekarla. The support for openRBRVR is out in OXRMC version 0.3.6 onwards.
• Improve OpenXR layer detection and error handling at startup.