revise DBMatrix::row_incre() and update_row().
revise DBMatrix::row_incre() and update_row().

add param "cols2" in row_incre() to increment another column list.
revise update_row() to store into "_cache_storage" first instead of "_db_storage".

izenecloud/izenelib,pombredanne/izenelib,izenecloud/izenelib,pombredanne/izenelib,izenecloud/izenelib,pombredanne/izenelib,izenecloud/izenelib,pombredanne/izenelib