Adding the Navier-Stokes example.

examples/CMakeLists.txt

examples/navier-stokes/Makefile

examples/navier-stokes/laxFridrichs.h

examples/navier-stokes/main.cpp

examples/navier-stokes/make-png-from-gnuplot

examples/navier-stokes/merge-figures

examples/navier-stokes/navier-stokes.cfg.desc

examples/navier-stokes/navierStokesSetter.h

examples/navier-stokes/navierStokesSetter_impl.h

examples/navier-stokes/navierStokesSolver.h

examples/navier-stokes/navierStokesSolverMonitor.h

examples/navier-stokes/navierStokesSolverMonitor_impl.h

examples/navier-stokes/navierStokesSolver_impl.h

examples/navier-stokes/share/examples/cavity

src/implementation/mesh/tnlGrid1D_impl.h

src/implementation/mesh/tnlGrid2D_impl.h

src/implementation/mesh/tnlGrid3D_impl.h

src/legacy/mesh/implementation/tnlGrid1D_impl.h

src/legacy/mesh/implementation/tnlGrid2D_impl.h

src/legacy/mesh/implementation/tnlGrid3D_impl.h