Guarantee to end http parsing after websocket upgrade

Also fuzz handshakes

Add threaded websocket server, skip broken examples

Only set sec-websocket-extensions if we have an offer

Update uS to v0.1.2

Disable TopicTree for now

Fix Http timeout regarding .end with backpressure

Don't write mark in the middle of streaming

Port load_test to SSL/non-SSL uSockets API

API CHANGE: ws.close -> ws.end, ws.terminate -> ws.close