common review JPS/YO. Addition of stat_columns code. Incomplete url_columns....

common review JPS/YO. Addition of stat_columns code. Incomplete url_columns. Filtering empty string params now applies to all methods except objectValues. Renaming to selection_expression (instead of stat_query).


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@1215 20353a03-c40f-0410-a6d1-a30d3c3de9de