Implement getBaseCategoryDict, a cached version of getBaseCategoryList which should be used to check if a base category is present (dict key searching is O(1), which is always better than list searching, even if sorted).


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@9709 20353a03-c40f-0410-a6d1-a30d3c3de9de