PSA: publish a new WD of Streams API on October 23

[Arthur Barstow]

The Streams API spec has significant changes since its last TR 
publication (November 2013). As such, this is an announcement of an 
intent to publish a new WD on October 23, using the latest ED as the basis:

<https://dvcs.w3.org/hg/streams-api/raw-file/tip/Overview.htm>
If anyone has any major concerns this plan, please speak up.

-Thanks, AB