Using new class PdmUiTreeViewWidget instead of QTreeView in
PdmUiTreeViewEditor. PdmUiTreeViewWidget handles drag leave events and
calls endDrag() on the model.
Cleaned up the responsibilities between Editor, model and View
Now model exposes translation between QModelIndex and PdmUiItem
Selection inteface implementation is handled by editor, and forwarded to View
Also started renaming of SlectionManager update enabeling
Pdm fields can contain a forward declared Pdm object without the include
file
VizFwk: Added VertexColoring shader to be able to use per vertex color
used from drawableGeo::setColorArray()
