modified_object_list must be defined even if the format is old.
getTemplateFormatVersion must be used against context instead of self.
Remove obsolete diff.
When getting business_template_include_sub_categories, obj must be
wrapped.
__init__ calls _clean instead of duplicating the code.
Override getTemplateFormatVersion, because template_format_version was
not set even in the new format.
build sets template_format_version to 1.
Rename the method clean to _clean, because __init__ does not want to
invoke a workflow method.


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@4695 20353a03-c40f-0410-a6d1-a30d3c3de9de