* vk: separate specular color
rsx: separate front color output from back color output
re-enable front-back diffuse lighting
vk: fix front face selection and actually enable face culling
* dx12: Hide constant-key blended visuals (by common use of factor, 1-factor)
* dx12: Fix 2 sided lighting when the shader does not compute both outputs
* vk/dx12: confirm that src register exists before copying for 2-sided lighting
Rebase on current master; Refactor vertex upload code
Fix build; Minor fixes
Start preparations for merge
Fix generic indexed drawing bugs
Define WIN32_KHR only for windows
Remove linking against vulkan-1.lib