WebSocket: Update WebSocket protocol to hybi-17
 https://bugs.webkit.org/show_bug.cgi?id=69910
Reviewed by Kent Tamura.
Essential changes between hybi-10 and hybi-17 are:
- Sec-WebSocket-Origin header has been renamed to "Origin".
- Sec-WebSocket-Version header value has been bumped to 13.
No new tests are necessary. pywebsocket has already been updated to the latest version
which understands the new protocol. Tests under http/tests/websocket/ should keep
passing.
* websockets/WebSocketHandshake.cpp:
(WebCore::WebSocketHandshake::clientHandshakeMessage):
(WebCore::WebSocketHandshake::clientHandshakeRequest):