[vtkusers] VTK 5.7 Qt4 build error

[Dean Inglis]

Hi Clinton,

the path for the cache entry was incorrect as:
QT_QTDESIGNER_INCLUDE_DIR:PATH=D:/Developer/Releases/MinGW/SHARED/Qt/QtDesigner

should have been:
QT_QTDESIGNER_INCLUDE_DIR:PATH=D:/Developer/Releases/MinGW/SHARED/Qt/include/QtDesigner

vtkQtChart, QVTK and QVTKWidgetPlugin are now building

thanks,
Dean