Thanks to this container state on freshly initialised packing list is draft.
 - convert miss and pack transition from automatic transition to workflow
   methods
 - add PackingList_calculatePacking which moves packing state to missing or
   packed using workflow method
Thanks to not using automatic transition, but workflow methods and after method
in calculate_packing it is easier to reuse such workflow in highly restricted
environments.


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@34060 20353a03-c40f-0410-a6d1-a30d3c3de9de