Merge branch 'develop' into 'master'

examples/ellipt.cc

examples/init/stokes.dat.2d

examples/navier_stokes.cc

examples/stokes0.cc

examples/stokes1.cc

examples/stokes3.cc

examples/vecellipt.cc

src/amdis/Assembler.hpp

src/amdis/Assembler.inc.hpp

src/amdis/DirichletBC.hpp

src/amdis/DirichletBC.inc.hpp

src/amdis/FileWriter.hpp

src/amdis/GridFunctionOperator.hpp

src/amdis/GridFunctions.hpp

src/amdis/Initfile.hpp

src/amdis/LocalAssemblerBase.hpp

src/amdis/Mesh.hpp

src/amdis/Operations.hpp

src/amdis/ProblemInstat.hpp

src/amdis/ProblemInstat.inc.hpp