Remove the done and error callbacks. The error callback is in an
error message. The done callback is replace with spa_pending.
Make enum_params take a callback and data for the results. This allows
us to push the results one after another to the app and avoids ownership
issues of the passed data. We can then extend this to handle the async
case by doing a _wait call with a spa_pending+callback+data that will
be called when the _enum_params returns and async result.
Add a sync method.
All methods can now return SPA_RESULT_IS_ASYNC return values and you
can use spa_node_wait() to register a callback when they complete
with optional extra parameters. This makes it easier to sync and
handle the reply.
Make helper methods to simulate the sync enum_params behaviour for
sync nodes.
Let the transport generate the sequence number for pw_resource_sync()
and pw_proxy_sync(). That way we don't need to keep track of numbers
ourselves and we can match the reply to the request easily.
Add signal handlers for daemon to shut down
Add destroy listeners for modules and do cleanup
Fix some leaks
Simplify port registration in new nodes
Hide some more data structures
Let the node implementation take care of the reuse_buffer signal because
then we can get to the graph nodes to find the destination port.
Destroy modules in core cleanup. Modules should undo everything they
have done.
Activate the link after we negotiated format and buffers.
