- Decouple DrmBackend and DrmDevice through Weak references
- Move EGL-WlBuffer related functionality into it's own trait
- Impl new trait by every struct that can theoretically bind the display although it is no rendering target (no EGLGraphicsBackend), e.g. DrmDevice
- Move texture binding into own struct `EGLDisplay` created by `bind_wl_display` that can be passed around freely
- Add device num to DrmDevice for HashMap storage
- Fixup and enable acceleration on drm and udev examples made possible by the previous changes.