The default texture map is a single white pixel.

Vulkan objects host GPU resources. We need to use containers
that don't call destructors on them, and we want the compiler to tell
us if its going to try. To do that, remove the copy constructors.

Also significant work on construction of CPU->GPU resource structs.

Also fix window-resize logic on macOS, where a window resize typically
triggers on the acquireImageKHR step, as opposed to Linux, where it
almost always triggered at the actually-working presentKHR stage.

Adds a variety of new objects and support for Wavefront .obj objects
with multiple meshes and one texture per-mesh, albeit only rendering
the first mesh of the object.

Also improves descriptor set layout, adds the `-v` argument to control
logging, and improves object loading, and begins the skeleton of
support for multiple draw calls per frame.