[cleanup][all] Update code to current dune core master (2.7-git). Also,

dune/common/smartptr.hh

dune/grid/cacheitgrid/CMakeLists.txt

dune/grid/cacheitgrid/backuprestore.hh

dune/grid/cacheitgrid/capabilities.hh

dune/grid/cacheitgrid/entity.hh

dune/grid/cacheitgrid/entitypointer.hh

dune/grid/cacheitgrid/entityseed.hh

dune/grid/cacheitgrid/geometry.hh

dune/grid/cacheitgrid/grid.hh

dune/grid/cacheitgrid/hierarchiciterator.hh

dune/grid/cacheitgrid/intersection.hh

dune/grid/cacheitgrid/intersectioniterator.hh

dune/grid/cacheitgrid/iterator.hh

dune/grid/cacheitgrid/twistutility.hh

dune/grid/cartesiangrid/capabilities.hh

dune/grid/cartesiangrid/dgfparser.hh

dune/grid/cartesiangrid/grid.hh

dune/grid/cartesiangrid/hostgridaccess.hh

dune/grid/cartesiangrid/hostgridinfo/alugrid.hh

dune/grid/cartesiangrid/intersection.hh