스프링 시큐리티 로그인 유지, 리멤버 미(remember-me)

http://docs.spring.io/spring-security/site/docs/3.0.x/reference/springsecurity-single.html#remember-me-persistent-token

http://jaspan.com/improved_persistent_login_cookie_best_practice


리멤버 미 예제
http://www.mkyong.com/spring-security/spring-security-remember-me-example/