Add changes file for 5.6.2

Change-Id: Ibb98081ddd226187212936949ca70bf1339c05aa
Reviewed-by: Venugopal Shivashankar <Venugopal.Shivashankar@qt.io>
Reviewed-by: Johan Helsing <johan.helsing@qt.io>

dist/changes-5.6.2

+Qt 5.6.2 is a bug-fix release. It maintains both forward and backward
+compatibility (source and binary) with Qt 5.6.0.
+
+For more details, refer to the online documentation included in this
+distribution. The documentation is also available online:
+
+  http://doc.qt.io/qt-5/index.html
+
+The Qt version 5.6 series is binary compatible with the 5.5.x series.
+Applications compiled for 5.5 will continue to run with 5.6.
+
+Some of the changes listed in this file include issue tracking numbers
+corresponding to tasks in the Qt Bug Tracker:
+
+  https://bugreports.qt.io/
+
+Each of these identifiers can be entered in the bug tracker to obtain more
+information about a particular change.
+
+
+Qt Wayland QPA Plugin
+-------
+
+ - Fixed drag and drop from the application to itself when running on Weston
+ - Improved the HIDPI support
+ - Fixed a crash when dragging a window with touch input and no pointer
+ - Fixed a crash on application exit
+ - Made it use the proper activation mechanism when using xdg_shell
+ - Fixed returning to the same window size when unmaximizing on xdg shell
+ - Fixed the window resize area being too big on the bottom and right edges