* backend support for new watch system (#134):
- support for watch via redis pubsub and websocket connection to backend
- can support watch from any number of crawler instances to support scaled crawls
- use /archives/{aid}/crawls/{crawl_id}/watch/ws websocket endpoint
- ws: ignore graceful connectionclosedok exception, log other exceptions
- set logging to info to instead of debug for now (debug logs all ws traffic)
- remove old watch apis in backend
- remove old websocket routing to crawler instance for old watch system
- oauth bearer check: support websockets, use websocket object if no request object
- crawler args: replace --screencastPort with --screencastRedis
9bd402fa17