added nginx_log_dir in rubber-nginx.yml to specify log dir of nginx
added rotate_logs task for mongodb to crontab
added rotate_logs task for memcached to crontab
Update nginx and passenger to the latest versions

Also add HTTP_X_QUEUE_START for NewRelic
Upgrade redis to 2.6.11
honor host option, add fakeroot option
fix typo fake_root -> fakeroot