There are some missing parts from this commit as these are the fairly
clean changes. Missing is building a separate set of pipelines for the
new render pass (might be able to get away from that), OIT heads texture
is flat rather than an array, view matrices aren't set up, and the
fisheye renderer isn't hooked up to the output pass (code exists but is
messy). However, with the missing parts included, testing shows things
mostly working: the cube map is rendered correctly even though it's not
displayed correctly (incorrect view). This has definitely proven to be a
good test for Vulkan's multiview feature (very nice).
I had debated putting the blending in the compose subpass or a separate
pass but went with the separate pass originally, but it turns out that
removing the separate pass gains 1-3% (5-15/545 fps in a timedemo of
demo1).
Lighting doesn't actually do lights yet, but it's producing pixels.
Translucent seems to be working (2d draw uses it), and compose seems to
be working.
