Merge branch 'cleanup/remove-vintage-code' into 'master'

dune/fufem/CMakeLists.txt

...em/assemblers/dunefunctionsboundaryfunctionalassembler.hh

dune/fufem/assemblers/transferoperatorassembler.hh

dune/fufem/discretizationerror.hh

dune/fufem/estimators/refinementindicator.hh

dune/fufem/functions/CMakeLists.txt

dune/fufem/functions/analyticgridfunction.hh

dune/fufem/functions/basisgridfunction.hh

dune/fufem/functions/coarsegridfunctionwrapper.hh

dune/fufem/functions/gridfunctionhelper.hh

dune/fufem/functions/vintagebasisgridfunction.hh

dune/fufem/functions/virtualdifferentiablefunction.hh

dune/fufem/functions/virtualgridfunction.hh

dune/fufem/functionspacebases/CMakeLists.txt

dune/fufem/functionspacebases/conformingbasis.hh

dune/fufem/functionspacebases/dofconstraints.hh

dune/fufem/functionspacebases/dunefunctionsbasis.hh

dune/fufem/functionspacebases/extensionbasis.hh

dune/fufem/functionspacebases/functionspacebasis.hh

dune/fufem/functionspacebases/p0basis.hh