fix broken prependContent, split form() into a few functions for easier overriding
fix broken prependContent, split form() into a few functions for easier overriding

derFreitag/mockup,plone/mockup,domruf/mockup,domruf/mockup,termitnjak/mockup,domruf/mockup,plone/mockup,derFreitag/mockup,termitnjak/mockup,domruf/mockup,derFreitag/mockup,termitnjak/mockup,plone/mockup,termitnjak/mockup,derFreitag/mockup