An attempt at Vulkan

So you are planning to write a compatibility layer, similar to Google ANGLE, instead of doing a full rewrite as it is being done in 2545? I really like this idea. It would help maintain OpenGL-based games without having to deal with aging OpenGL drivers. That is the same reasoning that led me to start working on implementing ANGLE as a backend in 2585. The key difference in your approach is that we would have access to Vulkan inside JME, which would give us the opportunity to progressively implement Vulkan functionality directly into the engine over time. It seems like a big project, if it can help make it more feasible, I believe you could consider targeting the smaller GLES 3.0 subset instead of full OpenGL. The engine is already essentially a GLES-based engine due to Android support, and everything that is OpenGL-only already has a GLES fallback.