Changes to align with latest WHAT WG Streams API specification:

* Changed the name of the ReadableStream attribute “input” to “readable” and the name of the WritableStream attribute “output” to “writeable”.
* Changed link to [STREAMS] to latest WHAT WG Streams specification.
* Corrected editorial in 6.2: “Closes the TCP socket. Returns the closedPromise that was created in the UDPSocket constructor.”
* Added comment that so far we assume default strategy, i.e. the ReadableStream’s and WriteableStream’s constructor’s last argument is omitted.
* Description of the semantics for the input argument functions to the WritableStream updated to be aligned with latest version of the WHAT WG Streams API specification.
- start() returns a promise that is resolved when the TCP connection has been established and rejected if the TCP connection attempt failed.
- write(chunk) returns a promise that is resolved if writing succeeded and rejected if writing failed.
- close() unchanged
- abort() added

Similar for UDP.