Vulkan layer for GPU offloading

 Typically you want to display an image rendered on a more powerful
 GPU on a display managed by an internal GPU. The layer in this package will
 direct rendering commands to a dedicated, more powerful GPU an when such an
 image is displayed it will be copied to the integrated CPU for displaying.
 .
 The user can activate offloading for individual applications by launching
 them with the "pvkrun" program.