added a changes for 5.5.0

Change-Id: Ia8a927c5bcfb45bc7a8c16d1c8ff75487fe71cdd
Reviewed-by: Giulio Camuffo <giulio.camuffo@jollamobile.com>

dist/changes-5.5.0

+Qt 5.5 introduces some new features and improvements as well as bugfixes
+over the 5.4 series. Better conformance with the QPA interface has been
+achieved, and there has been a focus on making QtQuick work reliably in
+Wayland Clients
+
+****************************************************************************
+*                            Qt Wayland General                            *
+****************************************************************************
+
+- Update Wayland protocol version to 1.4
+- brcm integration fixed
+- Added a class for converting shm formats
+
+****************************************************************************
+*                          Qt Wayland QPA Plugin                           *
+****************************************************************************
+
+- xdg-shell integration updated to work with weston 1.6
+- Improve popup handling
+- Added support for Qt WebEngine
+- Added support for setMask for input region
+- Fix for using QtQuick with the threaded renderer
+- Fixed fontrendering to be on par with the xcb plugin
+
+
+****************************************************************************
+*                              Qt Compositor                               *
+****************************************************************************
+
+- Only use Q_SLOTS and Q_SIGNALS in header files
+- Added a QWayland Output class
+- Added support for multiple input devices
+- Added public class for QWaylandClient