all renderers use  as the array for the template vars now, this name can be changed by passing the var_name parameter to the renderer in output_types.xml. Also, the template vars can be extracted (to mimic old SmartyView behavior) for all engines by setting th extract_vars parameter to true for the respective renderer in output_types.xml. All templates have access to  (the Renderer, getView() to get View instance, getContext() to get Context) now, too. closes #180