PDM configuration.
* Resource.py: moved some variation related properties to VariationRange.py.
* VariationRange.py: added optional and individial variation related
  properties.


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@20290 20353a03-c40f-0410-a6d1-a30d3c3de9de