Improve GPU-diffusion profiling. Add a full update ghost. fix advection_dir topology parameters. fix tools parameters. Add update ghosts test.

Add licence header. Add biblio (Noca)

Add new update ghosts (communicates full ghosts values on edges and corners). Fix usage of this synchronization on gpu operators.

Temp drag. Some tests fail (test_advection_nullVelocity, test_advection_randomVelocity) following merge with JM branch. To be fixed