[bugfix] install add headers from example directories

This should partially fix issue #2

dune/fem-dg/examples/advdiff/CMakeLists.txt

 dune_install( main.cc models.hh algorithmcreator.hh problems.hh)
 
-dune_add_subdirs( test )
+dune_add_subdirs( test problems )
 

dune/fem-dg/examples/advdiff/problems/CMakeLists.txt

+dune_install( deformationalflow.hh problem.hh problemQuasiHeatEqn.hh pulse.hh sin.hh)

dune/fem-dg/examples/dataio/CMakeLists.txt

-dune_install( checkedcheckpointcaller.hh  checkpointing.hh  models.hh  algorithmcreator.hh  problem.hh )
+dune_install( algorithmcreator.hh checkedcheckpointcaller.hh checkpointing.hh models.hh problem.hh )
 
 dune_add_subdirs( test )

dune/fem-dg/examples/euler/CMakeLists.txt

-dune_install( main.cc  models.hh  algorithmcreator.hh  problems.hh )
+dune_install( main.cc algorithmcreator.hh models.hh problems.hh )
 
-dune_add_subdirs( test ) 
+dune_add_subdirs( problems test )

dune/fem-dg/examples/euler/problems/CMakeLists.txt

+dune_install( chorjo.cc chorjo.hh problems.hh )

dune/fem-dg/examples/incompnavierstokes/CMakeLists.txt

-dune_install( main.cc incompnavierstokesalgorithm.hh  models.hh  algorithmcreator.hh  problems.hh  stokesmodel.hh )
+dune_install( main.cc algorithmcreator.hh incompnavierstokesalgorithm.hh models.hh problems.hh stokesmodel.hh subnavierstokesalgorithmcreator.hh subpoissonalgorithmcreator.hh substokesalgorithmcreator.hh  )
 
-dune_add_subdirs( test )
+dune_add_subdirs( problems test )

dune/fem-dg/examples/incompnavierstokes/problems/CMakeLists.txt

+dune_install( operatorsplitting.hh problem.hh )

dune/fem-dg/examples/navierstokes/CMakeLists.txt

-dune_install( main.cc ns_model.hh algorithmcreator.hh ns_model_spec.hh thermodynamics.hh passtraits.hh)
+dune_install( main.cc algorithmcreator.hh models.hh navierstokesflux.hh problems.hh thermodynamics.hh )
 
-dune_add_subdirs( test )
+dune_add_subdirs( problems test )

dune/fem-dg/examples/navierstokes/problems/CMakeLists.txt

+dune_install( nssmooth.hh nswaves.hh )

dune/fem-dg/examples/poisson/CMakeLists.txt

-dune_install( main.cc  gridinitializer.hh  models.hh  algorithmcreator.hh  problems.hh )
+dune_install( main.cc algorithmcreator.hh gridinitializer.hh models.hh problems.hh )
 
-dune_add_subdirs( test )
+dune_add_subdirs( problems test )

dune/fem-dg/examples/poisson/problems/CMakeLists.txt

+dune_install( benchmarkproblems.hh poissonproblem.hh )

dune/fem-dg/examples/stokes/CMakeLists.txt

-dune_install( main.cc models.hh  algorithmcreator.hh  problems.hh  stokesalgorithm.hh  stokesassembler.hh  tensorhelper.hh )
-     
-dune_add_subdirs( test )
+dune_install( main.cc algorithmcreator.hh models.hh problems.hh stokesalgorithm.hh stokesassembler.hh tensorhelper.hh )
+
+dune_add_subdirs( problems test )

dune/fem-dg/examples/stokes/problems/CMakeLists.txt

+dune_install( corner.hh problem.hh )