Add Direct Draw Surface plugin to documentation and changelog.

Change-Id: I866c65ecfbbe85822f8b8e9233098f56cb21d405
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>

dist/changes-5.3.0

+Qt 5.3 introduces many new features and improvements as well as bugfixes
+over the 5.2.x series. For more details, refer to the online documentation
+included in this distribution. The documentation is also available online:
+
+  http://qt-project.org/doc/qt-5.3
+
+The Qt version 5.3 series is binary compatible with the 5.2.x series.
+Applications compiled for 5.2 will continue to run with 5.3.
+
+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                                        *
+****************************************************************************
+
+ - Add read/write support for Direct Draw Surface images.

src/imageformats/doc/src/qtimageformats.qdoc

@@ -52,6 +52,7 @@ libraries. If not found, it may fall back on using a bundled copy (in
 
 \table
 \header \li Format \li Description                      \li Support      \li 3rd party codec
+\row    \li DDS    \li Direct Draw Surface              \li Read/write   \li No
 \row    \li MNG    \li Multiple-image Network Graphics  \li Read         \li Yes (bundled)
 \row    \li TGA    \li Truevision Graphics Adapter      \li Read         \li No
 \row    \li TIFF   \li Tagged Image File Format         \li Read/write   \li Yes (bundled)