We teardown all existing screencast_instances using the removed output
by destroying the frame, removing all timers and then marking the
instance as ready for teardown so we can destroy it after the last connected
session is closed.
Any wlr_screencopy_frame_v1 has to be destroyed before the connected
output can be removed. Otherwise wlr_screencopy_frame_v1_destroy
segfaults the whole program. To ensure this we will make all frame
callbacks safe to be triggered for a previous destroyed frame.
* Initial session support WIP
Remove libdrm dependency
Remove display from context, add dbus properties
Use random names for shm and pw_stream, init the stream only for new cast instances
Separate cast initialized flag from refcount, cleanup names and comments
* Refactor and stability improvements
Properly report xdp screencast implementation version
