* Add predicate category related keys.
* Update predicate category indexing method to support "no-left-join" version of predicate search.
* Use erp5_core revision 1601 or higher.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@36094 20353a03-c40f-0410-a6d1-a30d3c3de9de