Rework stream connect/disconnect from start/stop Start the stream in setcaps when the format is known. When the stream is already started in setcaps, send a format_change message instead.
When we get a new format, stop, disconnect and unref the old stream. In the future we should try to send a format change on the existing stream.
Rename src to pinos and fix all the include paths so that they contain pinos/ to avoid conflicts