Use std::shared_ptr instead of Dune::shared_ptr.

dune/fufem/any.hh

.../localassemblers/variablecoefficientviscosityassembler.hh

...fem/assemblers/localassemblers/vonmisesstressassembler.hh

...fufem/assemblers/localassemblers/weightedmassassembler.hh

dune/fufem/assemblers/transferoperatorassembler.hh

dune/fufem/functions/analyticgridfunction.hh

dune/fufem/functions/polynomial.hh

...ufem/functions/virtualfunctiontoboundarysegmentadapter.hh

dune/fufem/functions/vtkvirtualfunction.hh

dune/fufem/functiontools/basisidmapper.hh

dune/fufem/functiontools/gridfunctionadaptor.hh

dune/fufem/functiontools/vtkbasiswriter.hh

dune/fufem/makehalfcircle.hh

dune/fufem/makesphere.hh

dune/fufem/python/conversion.hh

dune/fufem/sharedpointermap.hh

dune/fufem/test/dunepythontest.cc