Compliant: adding constraint damping in python API

git-svn-id: svn://scm.gforge.inria.fr/svnroot/sofa/trunk@10287 b7f1a160-662a-0410-a6d8-bea165342f16
SofaPython: ADD "bwdInitGraph" python entry point in PythonScriptController

git-svn-id: svn://scm.gforge.inria.fr/svnroot/sofa/trunk@10288 b7f1a160-662a-0410-a6d8-bea165342f16