SofaTest: adding a more complex DAG test

git-svn-id: svn://scm.gforge.inria.fr/svnroot/sofa/trunk@11061 b7f1a160-662a-0410-a6d8-bea165342f16
FIX: LightManager useless opengl call to glViewport which can lead to render crash on non-gui based viewer

git-svn-id: svn://scm.gforge.inria.fr/svnroot/sofa/trunk@11062 b7f1a160-662a-0410-a6d8-bea165342f16
CGoGN : fixed a bug in cellMarker.

git-svn-id: svn://scm.gforge.inria.fr/svnroot/sofa/trunk@11063 b7f1a160-662a-0410-a6d8-bea165342f16