Follow cl-vk 75c1e87: the enum types of arguments and readers
The API reference and the page on swapchains name the enum types that
create-swapchain's keywords, the swapchain's readers, the physical device
type, the debug message severity, the current transform and results
have.
Describe cl-vk's conditions for misuse and its escape hatches
Misuse is a type-error where check-type can say what is wrong, and a
vk-error with a message otherwise; the struct macros' expansion-time
errors are vk-errors too. instance-commands, device-commands and
swapchain-images are escape hatches that refuse destroyed objects, and
swapchain-images has an entry of its own. device-queue takes :family
and :index. with-structs takes a foreign pointer for a field that
points to untyped memory. The generator no longer has *platforms*.
Follows cl-vk cae101e: the raw layer's structs, types and the loader's
library are cl-ffi's, the examples use cl-ffi's operators, and getting
started lists cl-ffi in the qlfile beside cl-vk.