Add an async result code and an event to signal the completion.
Use async return values to signal completion of a method and potential
state change.
Add selected format to port update message.
Make it possible to parse into a custom copy of the command memory.
Remove state change events from the elements, we now just update the
state.
Implement async results in the proxy element
Add support for removing buffers in the client.
Fix up pinossink
Deal with async return in the links.
Reserve 0,0 for stack allocated mem that we never free
Improve allocation in the link
Parse format and properties in-line, there is no need to allocate
memory.
Improve buffer cleanup in alsa
Add timestamps and offset to alsa
