cell locators: compatibility for polyhedra-polygon

The method vtkAbstractCellLocator::FindCell(double[3]) needs to allocate a weight array for the subrouting to work. The size of this array was hardcoded to be 32. In the instance of polyhedra and polygons, the weight array can need to be arbitrarely larger.

vtkAbstractCellLocator::BuildLocator() now has an implementation that updates the array size if the input is an unstructured grid or a poly data with polyhedrons or polygons.