Add note about porting a QtWebKit application to Qt 5

When using the widgets it is necessary to include QtWebKitWidgets now
so a note is added about that.

Change-Id: I81a36ecc7cac3e8efcfbe1bfa1e5446b1970c9ed
Reviewed-by: Jerome Pasion <jerome.pasion@digia.com>

doc/src/portingcppapps_toqt5.qdoc

@@ -46,6 +46,15 @@ This creates the \c animatedtiles executable. Try running the executable to see
 
 \image animatedtiles_snapshot.png "A snapshot of the \c animatedtiles application running on Ubuntu v12.04"
 
+A similar change is needed for porting Qt 4 applications using Qt WebKit to Qt 5. The following
+step-by-step instructions take you through the changes required to achieve this:
+
+\list 1
+   \li If using \c {#include <QtWebKit>}, add \c {#include <QtWebKitWidgets} in your source code.
+   \li Edit the pro file and add \c {QT += webkitwidgets} towards the end of the file.
+   \li Run qmake and make utilities to build the binary.
+\endlist
+
 \section1 Related topics
 \list
 \li \l {API Changes}

doc/src/portingguide.qdoc

@@ -56,6 +56,8 @@ The following list summarizes the changes in Qt 5:
        Quick (2.0) from now on to avoid binary breaks in the future.
    \li Qt3Support - This module is removed in Qt 5, so you must move away from
        this module before porting your codebase to Qt 5.
+   \li Qt WebKit - This module has been split into two, there is now a \l{Qt WebKit}
+       and a \l{Qt WebKit Widgets} module.
 \endlist
 
 \section1 Related Topics