Merge branch 'master' into xt+core_2.4_switchover_with_expectations_adjusted

.clang-format

.clang-format-3.7

.clang-format-3.8

dune/gdt/local/fluxes/godunov.hh

dune/gdt/operators/fv.hh

dune/gdt/test/hyperbolic/fv-discretization.hh

dune/gdt/test/hyperbolic/problems/default.hh

dune/gdt/test/hyperbolic/problems/fokkerplanck/twobeams.hh

dune/gdt/test/linearelliptic/discretizers/cg.hh

dune/gdt/test/linearelliptic/discretizers/ipdg.hh

dune/gdt/test/linearelliptic/eocexpectations.hh

.../gdt/test/linearelliptic/swipdg-estimator-expectations.hh

...liptic/swipdg-estimator-expectations/ao2013-2dalugrid.cxx

...iptic/swipdg-estimator-expectations/esv2007-2dalugrid.cxx

...lliptic/swipdg-estimator-expectations/spe10-2dalugrid.cxx

dune/gdt/test/linearelliptic/swipdg-estimator-testcases.hh

dune/gdt/test/linearelliptic/swipdg-estimators.hh

dune/gdt/test/projections/base.hh

dune/gdt/test/projections__l2__cg_fem.cc

dune/gdt/test/projections__l2__cg_pdelab.cc