sql_gen.py: Added row_count

db_xml.py: put_table(): Count # rows and update in_row_ct_ref once all columns have been processed. Don't pass in_row_ct_ref to recursive calls because it should only be increased once.

db_xml.py: put_table(): Added in_row_ct_ref param to store the # of input rows processed. Renamed row_ct_ref param to row_ins_ct_ref to distinguish it from new in_row_ct_ref param.

sql_gen.py: MockDb.esc_name(): Don't use sql.esc_name_by_module() to avoid circular dependency on sql module

sql.py: put_table(): Factored out mk_select() calls in calls to run_query_into_pkeys() into new helper function insert_into_pkeys()

sql.py: put_table(): run_query_into_pkeys() calls use order_by=None in their select statements because there is a pkey, so order (row #) does not matter

db_xml.py: put_table(): Subset in_table if limit != None or start != 0. start param defaults to 0 again to avoid subsetting the table when starting from row 0 (with no limit).

db_xml.py: put_table(): Don't pass limit, start recursively, because the table subsetting will happen only once in the first invocation of the function. Moved limit, start params to end since they are not passed recursively. start param no longer defaults to 0 because this is not needed since sql.put_table() now sets start to 0 where needed.

sql.py: put_table(): Removed limit and start params because they were never fully implemented, and because it's simpler to just have the caller subset their input table

lists.py: Added uniqify()