Use a POD for the format body. This allows us to more easily build
and copy the formats.
Remove obsolete code to make video and audio formats.
Use SpaVideo/AudioInfo to keep track of formats. Make functions to parse
the format into the structures.
Update plugins
Move offset, size and stride to separate chunk structure that we
can keep in shared memory.
Add shared metadata type to hold the memory block holding the
metadata.
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.
Move the proxy plugin to the client-node
Move serialization code to pinos because its specific to pinos
Move some functions to the .h files
Make the mapper dynamic
