overload variation_base_category, the default variation_base_category should be
defined on preference
(preferred_apparel_model_individual_variation_base_category_list).
- add init_script on Apparel Model Colour Variation and Apparel Model
Morphology portal_types to automatically set base_category using preferences
- remove variation_base_category from ApparelModelColourVariation
PropertySheet, now it's not needed to overload this property since it should
be define throught preferences
- add field my_variation_base_category on ApparelModelColourVariation_view and
ApparelModelMorphologyVariation_view to show which variation_base_category is
used

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@29593 20353a03-c40f-0410-a6d1-a30d3c3de9de