Support MariaDB GTID in binlog replication handshake with MariaDB 10 Slaves

(1) Use GTID in handshake with MariaDB Master server
When
CHANGE MASTER TO master_host='<host-ip>', master_user='<usr>', master_password='<password>', master_use_gtid=slave_pos
is executed on MaxScale, request the master to send binlog starting from GTID corresponding to slave_pos; where slave_gtid_pos is the last

(2) Accept GTID in handshake from a MariaDB Slave. When Slave requests MaxScale to send binlog starting from slave_pos - start sending binlog record to the particular slave from the GTID corresponding to requested slave_pos