* Bug: In Hurricane, in NetlistWidget CTOR, the horizontal header was set
up assuing that there was (at least) three sections (column) in the
model, which was wrong. Now it is done in the setCell() method which
know the exact number of sections.
It was a bug in both Qt 4 & 5, but was showing only under Qt 5.
* New: In Hurricane, added hierarchy browser in the controller.
The hierarchy is presented as a tree. New MVC, HierarchyInformations,
HierarchyModel and HierarchyBrowser.
When using a data model which is not directly connect inside the
model, we must use the internalPointer field of the QModelIndex.
But this field is also used by the QSortFilterproxymodel, this
prevent using it with a Tree model.
The filter is directly implemented and is specific to each
Instance entry.
* Change: In CellWidget & CellWidget::State, now store the Cell and
a Path, this way we can keep track of the hierarchy when browsing.
The Path is in the State and so propagated back to the Controller.
* Change: In HierarchyCommand, use the Path with setCell().
Jean-Paul Chaput