Quick and Dirty GMRES solver for DDM: seems to work :-D \o/ !!!
Tested with emda, oo2 and osrc: gives same results on high order 3D case as old Jacobi version.


git-svn-id: https://geuz.org/svn/gmsh/trunk@18481 59c8cabf-10d6-4a28-b43f-3936b85956c4