Remove the old PinosBuffer object and replace it with SpaControl, this
communication protocol is designed to make it possible to implement
remote nodes and so it is moved to Spa.
Move SpaBuffer into to API
Work on easier API to make formats, implement enumeration and support
for all formats in v4l2.
Improve format output in -inspect
Add more buffer types to add and remove memory shared memory between the
server and client. We would like to send buffers only once and then
simply reference them by index.
Do format negotiation and stream start with a START message.
