ENH computing final objective in subgradientSSVM and NSlackSSVM.
FIX computation of primal objective in utils, add test.
Add "objective_" function to ssvm base class, refactor.
FIX call logger after the last call to compute the objective function...
FIX objective for rescale_C.
FIX Also fix SubgradientLatentSSVM objective curve.
Fix objective computeation in SubgradientLatentSSVM.