Remove the frame argument from the builder, we can use the builder
allocated frames.
Add deref function to builder to make it more flexible later.
Add some more recursion depth checks in the parser.
Improve props filter, also filter other types.
Make enum_params and set_param to configure properties, format
and other parameters. This allows us to remove some duplicate
code and make the properties and parameters much more extensible.
Use the object id to mark the id of the parameter.
Remove the spa_format and spa_props.
We can now make the client-node easier by merging the various
format methods into the params.
Make the stream API more powerful now that we can pass params
around.
Remove signals.
Rename callbacks -> events, use listeners to listen for events.
Callbacks are still used in spa for things you can listen to only
once.
