Rework the access checks.
Add owner field to more objects to do access control checks
Make sure the object global is set in the object before signaling the
new global.
Remove the node state. The state of the node is based on the state
of the ports, which can be derived directly from calling the port
methods. Track this state in the Port instead.
Add a mixer module that puts a mixer in from of audio sinks. This allows
multiple clients to play on one sink (still has some bugs). do some
fixes in the mixer and the scheduler to make this work.
Use counters instead of void* to iterate items. This simplifies some
things and makes it easier to do over the wire.
Add format description to NodeInfo and use this to add format
descriptions to pinos devices.
Small fixes to fix leaks and crashes.
