Moved and renamed initAfterReadRecursively, setupBeforeSaveRecursively
and resolveReferencesRecursively to XmlObjectHandle. Updated unit tests.
Removed resolveReferences() from PdmPtrField.
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()