Revision control

++ Qt 5.9 introduces many new features and improvements as well as bugfixes
++ over the 5.8.x series. For more details, refer to the online documentation
++ included in this distribution. The documentation is also available online:
++
++
++ The Qt version 5.9 series is binary compatible with the 5.8.x series.
++ Applications compiled for 5.8 will continue to run with 5.9.
++
++ Some of the changes listed in this file include issue tracking numbers
++ corresponding to tasks in the Qt Bug Tracker:
++
++
++ Each of these identifiers can be entered in the bug tracker to obtain more
++ information about a particular change.
++
++ ****************************************************************************
++ * Library *
++ ****************************************************************************
++
++ - QWebSocketServer
++ * [QTBUG-56129] SslMode::NonSecure enumerator now always has the same
++ value (1) regardless of SSL being enabled or disabled.
++ * [QTBUG-54276] Added a member function to handle external QTcpSocket,
++ upgrading it to a QWebSocket.
++ * [QTBUG-56414] Server now deletes a websocket when a 'disconnected'
++ signal is received.
++ - QWebSocketHandshakeRequest
++ [QTBUG-57357] Fixed the parsing of port in handshake requests.
++ - QWebSocketDataProcessor
++ [QTBUG-55506] Call clear() before emitting textMessageReceived or
++ binaryMessageReceived to avoid data corruption in case a slot blocks
++ (for example, entering a nested modal loop while showing this message)
++ while socket receives more data.
++ - QQmlWebSocket
++ * [QTBUG-58278] Fix setUrl: only call open() if the 'active' property is
++ true.
++