Implement per channel volume on channelmix. Extend control on stream to
take an array of values when possible.
Remove name argument from pw_node_new and pw_device_new. We can pass
this as a property instead.
Improve properties on nodes to more closely match what pulseaudio does.
Don't let the monitor do too much with the udev properties but let the
session manager set the description and icon-names.
Remove some change_mask flags for things that don't change in
introspect. Use the flags to mark changes in -cli and -monitor.
Remove override for resources, it can't work in general.
Rename method to add_object_listener to add a listener for
events/methods from the remote object.
Rename some methods to _call to call the interface and _notify
to notify the listeners.
Remove unused client event to be notified of resource
implementations.
