Session load to use message()

[Eliseu Monar dos Santos]

Because it uses session library from CI Core, I had to follow two steps to get messages working correctly:

1. Assign an encryption key in config/config.php;
2. Autoload the session library in config/autoload.php:

   $autoload['libraries'] = array(..., 'session');

Is there a way not to use sessions? I didn't figure out why.

Thanks for the best CI template library!