Merge remote-tracking branch 'remotes/berrange/tags/pull-qio-2017-10-04-1' into staging

Merge qio 2017/10/04 v1

# gpg: Signature made Wed 04 Oct 2017 13:23:04 BST
# gpg:                using RSA key 0xBE86EBB415104FDF
# gpg: Good signature from "Daniel P. Berrange <dan@berrange.com>"
# gpg:                 aka "Daniel P. Berrange <berrange@redhat.com>"
# Primary key fingerprint: DAF3 A6FD B26B 6291 2D0E  8E3F BE86 EBB4 1510 4FDF

* remotes/berrange/tags/pull-qio-2017-10-04-1:
  io: add trace events for websockets frame handling
  io: Attempt to send websocket close messages to client
  io: Reply to ping frames
  io: Ignore websocket PING and PONG frames
  io: Allow empty websocket payload
  io: Add support for fragmented websocket binary frames
  io: Small updates in preparation for websocket changes
  ui: Always remove an old VNC channel watch before adding a new one
  io: use case insensitive check for Connection & Upgrade websock headers
  io: include full error message in websocket handshake trace
  io: send proper HTTP response for websocket errors

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>