Doc: update info on Qt Versions in Build & Run options

Update screenshot and add a new one.

Change-Id: I6e2845bbc31474e32c307982fd380a42722d5367
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>

doc/src/projects/creator-projects-qt-versions.qdoc

@@ -53,22 +53,27 @@
 
             \li Select \gui {Tools > Options > Build & Run > Qt Versions > Add}.
 
+            \li Select the qmake executable for the Qt version that you want to
+                add.
+
+            \li Select the Qt version to view and edit it.
+
                 \image qtcreator-qt4-qtversions-add.png
 
-            \li Select the directory where the qmake executable is located.
-
-                \QC automatically determines the path to the binaries in
-                the Qt installation and displays it in the \gui{qmake location}
-                field.
-
             \li In the \gui{Version name} field, edit the name that \QC
                 suggests for the Qt version.
 
-            \li In the \gui Helpers section, you can build the debugging
+            \li In the \gui{qmake location} field, you can change the qmake
+                location.
+
+            \li In the \gui Helpers section, select \gui Details to build the debugging
                 helpers that are available for the Qt version. This is
                 necessary, because the internal data structures of Qt can
                 change between versions. For more information, see
                 \l{Using Debugging Helpers}.
+
+                \image qt-creator-debugging-helpers.png
+
             \li If the Qt version is for Blackberry or QNX, enter the path
                 to your installed Blackberry NDK or QNX SDK in the
                 \gui {Blackberry Native SDK} or \gui{QNX SDK} field respectively.