Clarify Qt Quick Controls documentation

We don't fully know the extent the Qt Quick Controls documentation and its presence in Qt 5.1

This task is to clarify and to remind people about the Qt Quick Controls in Qt 5.1

If we do have Qt Quick Controls in Qt 5.1, things needed to be done are:

-fit Qt Quick Controls in the UI story
-edit "QML Application Developers Resource" documentation to include Qt Quick Controls, refer to Qt Quick Designer
-polish the documentation
-make sure the docs are packaged and shipped with a .qch file