Add changes-5.0.2 file

Change-Id: Ic3edfb9336b0e56f887f7cc7315d35f4e6110362
Reviewed-by: Iikka Eklund <iikka.eklund@digia.com>

dist/changes-5.0.2

+Qt 5.0.2 is a bug-fix release. It maintains both forward and backward
+compatibility (source and binary) with Qt 5.0.0 and 5.0.1.
+
+For more details, refer to the online documentation included in this
+distribution. The documentation is also available online:
+
+  http://qt-project.org/doc/qt-5.0/
+
+Some of the changes listed in this file include issue tracking numbers
+corresponding to tasks in the Qt Bug Tracker:
+
+  http://bugreports.qt-project.org/
+
+Each of these identifiers can be entered in the bug tracker to obtain more
+information about a particular change.
+
+
+****************************************************************************
+*                           General                                        *
+****************************************************************************
+
+ - This release contains only minor code improvements.