Back to previous commit to (try to) fix bug in git : it loses all history in case of file/rep renaming.

Fix usage of scales offset. Allow 2D topologies for scales. Removing assertion in continuous operators (both resolution and topology)

update velocity correction (fix bug --> add normalization with domain length for mean vorticity computation)

Fix OpenCL devices exploring at parmes building for non opencl environments. Add a Froggy environment configuration file.

Update single precision patch. Fix OpenCL default platform and device id for building in non-OpenCL environment.

re-initialize force to zero at the begin of apply --> fix most of the parallelism problems, but there are still some discrepencies in the solution depending on the number of proc used. These discrepencies are due to the last term of the surface integrals, involving the deformation tensor. Moreover, the last contribution of these surface integrals has been corrected (some terms where missing)