Send a command stream over the socket.
Implement a new buffer object that holds the data and commands.
Make iterator and builders to parse and construct buffers.
Rework gstreamer elements to use new API for creating and parsing
buffers.
Add _release_buffer to notify a stream when we are done processing the
buffer. This will eventually go all the way to the server and will allow
us to do more complicated buffer management.
Add instrospection of client and source-output.
Add properties to source-output and to CreateSourceOutput/Input
Add helper to fill properties of context.
Add client-name to pinossrc and pinossink
Improve test-subscribe to show all new introspection details.
Add a mainloop wrapper that runs the mainloop in a separate thread and
has some synchronization primitives.
Use new mainloop in gstreamer source and sink elements
