The proxy API is the one that we would like to expose for applications
and the other API is used internally when implementing modules or
factories.
The current pw_core object is really a context for all objects so
name it that way. It also makes it possible to rename pw_core_proxy
to pw_proxy later.
Make a set-prop command to set a property from the config file
into a pw_properties. Pass this to the pw_core_new() and the
main-loop to tweak some stuff.
Move some warns to errors
Sometimes we insert NULL into the client object map to mark the object
freed. Now that the map also returns those NULL's, don't try to free
them.
Small cleanups
Make some port methods private.
Add hooks that contain protocol specific interfaces that can be used
to extend the protocol. This makes it possible to add new interfaces
to the protocol and implement the protocol specific data transport.
Move these protocol specific extension to the extensions directory.
