NewtonSolver now working for stiff systems with projective constraints.

WARNING: at the end of system assembly, H is replaced with PT.H.P .
In LDLTSolver, a very small identity matrix is added to make the matrix definite. This is tunable using attribute LDLTSolver::regularize.

TODO: make it work for compliant systems.

git-svn-id: svn://scm.gforge.inria.fr/svnroot/sofa/trunk@10434 b7f1a160-662a-0410-a6d8-bea165342f16
NewtonSolver tests, and some cleaning in the test framework.

WARNING: added attribute accumulateComplianceForces to MechanicalParams. This flag means that compliance forces must be accumulated as well as standard forces. This should have no impact on other classes than NewtonSolver.

Moved some scene modeling helpers from Solver_test to SceneCreator. Move vector assembly visitors too.

Removed a couple of warnings.

git-svn-id: svn://scm.gforge.inria.fr/svnroot/sofa/trunk@10435 b7f1a160-662a-0410-a6d8-bea165342f16
Refactoring the solver test framework.

WARNING In VectoOperations, changed input parameters from core::MultiVecId.
 to core::ConstMultiVecId. Added vector operations to compute arbitrary vector norms, including the infinite norm.

Moved scene creation methods from SolverTest and CompliantTest to SceneCreator.

git-svn-id: svn://scm.gforge.inria.fr/svnroot/sofa/trunk@10436 b7f1a160-662a-0410-a6d8-bea165342f16
Updated documentation of Compliant: ode matrices are now added a tiny diagonal matrix to avoid indefinite matrices created by projective constraints.

git-svn-id: svn://scm.gforge.inria.fr/svnroot/sofa/trunk@10437 b7f1a160-662a-0410-a6d8-bea165342f16
fix compilation

git-svn-id: svn://scm.gforge.inria.fr/svnroot/sofa/trunk@10438 b7f1a160-662a-0410-a6d8-bea165342f16