BUGFIX Using actual step instances instead of half-complete ArrayData templates in MultiForm->getAllStepsLinear()/getAllStepsRecursive(). Linking current form instance on these steps, and ensuring the title has a fallback to classname globally (not just when retrieving steps through getAllSteps*() methods)
BUGFIX Always fall back to creating a new step (in case the session or request data is invalid)
ENHANCEMENT Allowing $filter argument in MultiForm->getSavedSteps()
BUG Don't call MultiFormStep->loadData() twice
BUG Write current step to session when creating it
Backwards compat (FieldList fallbacks)