Make a main-loop object with associated helper functions to handle async
methods.
rtloop -> data_loop
Handle async results a lot better.
Remove REMOVE_MEM command. We don't need it.
Handle stream memory updates better.
spa_serialize -> pinos_serialize
Improve PinosPort, move links to the object and make it part of
PinosNode
Work on improving signals to react to changes in the graph
Error when a client-node becomes unlinked, like when removing a camera.
