input.Makefile: Configuration: Removed debug var since it's not used in the Makefile

db_xml.py: put_table(): put_table_(): Fixed bug where row_ins_ct_ref needed to be passed recursively to put_table() as keyword arg, because the in_row_ct_ref is not passed recursively

db_xml.py: put_table(): _simplifyPath: Parse "next" XPath param to extract col name of next level's pkey

bin/map: by_col: xml_func.strip(): Don't remove _simplifyPath because it is now handled by db_xml.put_table()

db_xml.py: put_table(): Added basic special handling for structural XML functions, which for now just skips the function

xml_func.py: strip(): Added preserve param for XML functions not to remove

db_xml.py: put_table(): Handle forward pointers in translation-to-sql_gen step instead of in XML-tree-parsing step, so that special handling for structural XML functions can use the parsed tree before any sql.put_table() processing takes place

xml_dom.py: Added is_node()

sql.py: table_row_count(): Pass start=0 to mk_select() to avoid "SELECT statement missing a WHERE, LIMIT, or OFFSET clause" warnings

sql.py: put_table(): Handle unknown exceptions by returning NULL for all rows. Refactored Missing mapping for NOT NULL column handling to use new helper function remove_all_rows().