use backend.verbose in newMatrix and nlSolve
start work on periodic boundary conditions
use periodic information from gmsh and fill out our mesh data structure
we start first by rewriting/testing the 2D part, the 3D part should come easily
@feelpp/feelpp update issue #62

Conflicts:
	doc/manual/laplacian/periodic.cpp
	feel/feelfilters/gmsh.hpp
	feel/feelfilters/gmshhypercubedomain.cpp
	feel/feelfilters/importergmsh.hpp
renamed .cpp file
++verbose regarding creating repository
read cfg file only if found
_periodic is an option of createGMSHMesh
Merge branch 'develop' of https://github.com/feelpp/feelpp into develop
@ranine, @mszopos stokes examples using ginac, the documentation needs to be updated
++verbose on .cfg being read