Reuse the previous x solution as initial guess in the PCG

git-svn-id: svn://scm.gforge.inria.fr/svnroot/sofa/trunk@9489 b7f1a160-662a-0410-a6d8-bea165342f16
UPDATE: [DeformableOnRigidFrameMapping] implement handleTopologyChange which call apply on position (and rest position) when TRIANGLESADDED so that the new triangles vertices positions are up to date. 

git-svn-id: svn://scm.gforge.inria.fr/svnroot/sofa/trunk@9490 b7f1a160-662a-0410-a6d8-bea165342f16
update Flexible: ellipsoid visualization and openmp parallelization in deformation mapping base class

git-svn-id: svn://scm.gforge.inria.fr/svnroot/sofa/trunk@9491 b7f1a160-662a-0410-a6d8-bea165342f16
fixed gcc compilation

git-svn-id: svn://scm.gforge.inria.fr/svnroot/sofa/trunk@9492 b7f1a160-662a-0410-a6d8-bea165342f16