mariadb10.0: follow the field type change
mariadb10.0: follow the field type change

Since MariaDB 10.0.37, the following field in FOREIGN_KEY_INFO is
changed.

LEX_STRING *update_method ->
enum_fk_option update_method

LEX_STRING *delete_method ->
enum_fk_option delete_method

mroonga/mroonga,mroonga/mroonga,mroonga/mroonga,mroonga/mroonga