Rename and remove unused code

appl/coupling-ff-pm/monolithic/2pspatialparams.hh

appl/coupling-ff-pm/monolithic/README.md

appl/coupling-ff-pm/monolithic/ffproblem.hh

appl/coupling-ff-pm/monolithic/interface/CMakeLists.txt

appl/coupling-ff-pm/monolithic/main.cc

appl/coupling-ff-pm/monolithic/models/CMakeLists.txt

...pling-ff-pm/monolithic/models/ex_models_coupling_ff-pm.cc

...ng-ff-pm/monolithic/models/ex_models_coupling_ff-pm.input

appl/coupling-ff-pm/monolithic/models/ex_models_ffproblem.hh

appl/coupling-ff-pm/monolithic/models/ex_models_pmproblem.hh

appl/coupling-ff-pm/monolithic/params.input

appl/coupling-ff-pm/monolithic/pmproblem.hh

appl/coupling-ff-pm/monolithic/turbulence/CMakeLists.txt

...-pm/monolithic/turbulence/ex_turbulence_coupling_ff-pm.cc

.../monolithic/turbulence/ex_turbulence_coupling_ff-pm.input

...ng-ff-pm/monolithic/turbulence/ex_turbulence_ffproblem.hh

...ng-ff-pm/monolithic/turbulence/ex_turbulence_pmproblem.hh