xml_func.py: process(): Refactored to emphasize special handling for row-based and column-based modes. In row-based mode, always use a DB relational function over a local XML function when possible, to faciliate testing of DB relational functions in row-based mode. (The shadowed local XML version will still be tested in non-DB modes, such as outputting to intermediate XML files.)
xml_func.py: process(): Refactored to emphasize special handling for row-based and column-based modes. In row-based mode, always use a DB relational function over a local XML function when possible, to faciliate testing of DB relational functions in row-based mode. (The shadowed local XML version will still be tested in non-DB modes, such as outputting to intermediate XML files.)