Tracking of Frames, so that only one unique one can exist at a time
(gles does not allow multiple frames being rendered in parallel)
lead to very unfriendly lifetime-heavy code. A renderer is already
*unique*, just move the code there and add an error variant to catch
misuses.
- Since a lot of functionality is now in smithay's rendering module
we can get rid of shm_load, shaders and the glium dependency.
- glium_drawer becomes drawing and only features some code to get from surfaces
to textures for any(!) renderer.
(Should probably moved into smithay at some point as well.)
- buffer_utils is only necessary to query the buffer size anymore.
- disable egl-buffer support temporarily