[Kde-bindings] Containers passed by reference

[David Palacio]

This is similar to the QImage::bits one. In the Okular bindings a QVector is 
marshalled to a Ruby array but the original QVector is never updated. This is 
not the expected behaviour by Okular.

virtual bool   loadDocument (const QString &fileName, QVector< Page * > 
&pagesVector)=0
is the c++ signature of a method that needs to be implemented in a generator. 
pagesVector is a QVector& that will be updated inside this method.

I have confirmed, on the C++ side, that the pagesVector has zero size.

This would need a special case: create a Ruby Array outside the method and 
pass it as an argument. When the method finishes, update the QVector.