The console background is missing, and scaled vs unscaled (currently
always scaled) 2d, but otherwise everything seems to work. Lots of
places to clean up, though.
Short wrappers for Draw functins are in vid_render_vulkan.c so the
vulkan context can be passed on to the actual functions. The 2D shaders
are set up similar to those in glsl, but with full 32-bit color (rgba)
support instead of paletted. However, the textures are not loaded yet,
nor is anything bound.
