mysql: set utf-8 by default

$ cd /etc/mysql
$ sudo nano my.cnf

[client]
default-character-set   = utf8

[mysqld]
init_connect='SET collation_connection = utf8_general_ci'
init_connect='SET NAMES utf8'
character-set-server=utf8
collation-server=utf8_general_ci
skip-character-set-client-handshake

[mysql]
default-character-set   = utf8

$ sudo service mysql restart