Follow autoconf capitalization conventions
Don't expose driver specific API
Add pitch field to wld_drawable
Separate non-wayland specific parts of wayland-drm

Now, applications can use hardware independent DRM drawables without
using wayland.
Don't automatically export DRM drawable to PRIME
Just use uint32_t instead of enum wld_format

Forward declarations of enum don't really make sense.
drm: Add buffer import support
Don't crash on global_remove
Rework configure options
drm: Add method to get buffer handle
Add write operation
Style
intel: Don't tile buffers if width is small
Add map operation
Style: Remove redundant static declaration