qdoc3: qdoc supports \depends in 4.8

qdoc3: qdoc supports \depends in 4.8

This is what you write...

/*!
\example designer/calculatorbuilder
\depends examples/qmlapplicationviewer
\title Calculator Builder Example

This is what you get...

<example name="Calculator Builder Example"
        docUrl="qthelp://com.trolltech.qt.480/qdoc/designer-calculatorbuilder.html"
        projectPath="designer/calculatorbuilder/calculatorbuilder.pro"
        imageUrl="qthelp://com.trolltech.qt.480/qdoc/images/calculatorbuilder-example.png">
<description><![CDATA[The Calculator Builder example shows how to create a user interface from
             a Qt Designer form at run-time, using the QUiLoader class.]]></description>
<tags>calculator,builder</tags>
<fileToOpen>designer/calculatorbuilder/main.cpp</fileToOpen>
<depends>../../examples/qmlapplicationviewer</depends>
</example>

Task-number:  QTBUG-22838