This splits up render pass creation so that the creation of the various
resources can be tailored to the needs of the actual render pass
sub-system. In addition, it gets window resizing mostly working (just
some problems with incorrect rendering).
Things are a bit of a mess with interdependence between sub-module
initialization and render pass initialization, and window resizing is
broken, but the main render pass rendering to an image that is then
post-processed (currently just blitted) is working. This will make it
possible to implement fisheye and water warp (and other effects, of
course).
When working, this will handle the output to the swap-chain images and
any final post-processing effects (gamma correction, screen scaling,
etc). However, currently the screen is just black because the image
for getting the main render pass output isn't hooked up yet.
