removed EntityPointer warnings

dune/fem-dg/assemble/primalmatrix.hh

dune/fem-dg/misc/dgnorm.hh

dune/fem-dg/operator/adaptation/adaptation.hh

dune/fem-dg/operator/adaptation/estimator.hh

dune/fem-dg/operator/adaptation/estimatorbase.hh

dune/fem-dg/operator/adaptation/utility.hh

dune/fem-dg/operator/dg/assembled/cdgprimaloperator.hh

dune/fem-dg/operator/dg/assembled/cdgrowwise.hh

dune/fem-dg/operator/dg/discretemodelcommon.hh

dune/fem-dg/operator/dg/fluxdiscretemodel.hh

dune/fem-dg/operator/dg/primaldiscretemodel.hh

dune/fem-dg/operator/fluxes/dgprimalfluxes.hh

dune/fem-dg/operator/fluxes/mhdfluxes.hh

dune/fem-dg/operator/limiter/limiterdiscretemodel.hh

dune/fem-dg/operator/limiter/limitpass.hh

dune/fem-dg/pass/assembleddiffusionpass.hh

dune/fem-dg/pass/dgmodelcaller.hh

dune/fem-dg/pass/dgpass.hh

dune/fem-dg/pass/threadpass.hh

dune/fem-dg/stepper/ellipticalgorithm.hh