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
Keep state variable to enumerate things. This allows us to remove the
expectation that the same index will give the same item.
Use a new rectangle type for video size. When enumerating sizes, this
allows us to specify relations between width and height more easily.
Remove the struct and bytes type, they are like pointer.
Add filter to enum_formats to speed up enumerations.
Add generic pointer metadata type that is copied on import
Pass array of pointers to SpaBuffers in use_buffers.
Make sure we use the same data and metadata as the imported buffer.
Remove the thread from alsa sink and use the pollfd event.
Make it possible to pass multiple fds in one pollfd event
Add 3 callbacks to the pollfd event and add support for timeouts
