Results 1 comments of hfcrwx

Update: 1. zero copy MYSQL_RES: mysql_use_result, mysql_fetch_row_* -> **mysql_store_result_*** use new callback function: std::function 2. change MariaDBClient to a single-threaded version (as Hiredis, Curl) 3. refactors Test successfully with MariaDB-Server/MySQL-Server...