refs #12 fix mysql bug 47719 for show engine status to propagate error
refs #12 clustering key grammar
refs #12 tweak query plans for clustering keys
refs #12 hot optimize table
refs #12 fast updates and upserts
refs #12 add bulk insert detector from mariadb
ref #12 fix updates of value(x) expressions. return type INSERT_VALUE_ITEM in Item_insert_value class.
refs #12 expand row format display width.