Viewport and FOV updates are now separate so updating one doesn't cause
recalculations of the other. Also, perspective setup is now done
directly from the tangents of the half angles for fov_x and fov_y making
the renderers independent of fov/aspect mode. I imagine things are a bit
of a mess with view size changes, and especially screen size changes
(not supported yet anyway), and vulkan winds up updating its projection
matrices every frame, but everything that's expected to work does
(vulkan errors out for fisheye or warp due to frame buffer creation not
being supported yet).
Regardless of whether the sky is spinning or not, the matrix needs to be
updated with the current origin in order to get the direction vector
right in the shader. Also, it's in the update that the required x-y
plane rotation gets in so the skies move in the correct direction.
This should fix the horrid frame rate dependent behavior of the view
model.
They are also in their own descriptor set so they can be easily shared
between pipelines. This has been verified to work for Draw.
