debugged assignement operator of vertex element:    the point has been copied, but _not_ the id ..    --> works now, regressions ran through
debugged assignement operator of vertex element:
   the point has been copied, but _not_ the id ..
   --> works now, regressions ran through

viennagrid/viennagrid-dev,viennagrid/viennagrid-dev,viennagrid/viennagrid-dev