double escaped text in drupal_set_message()

l() already does a check_plain() on the text you give it, so since we were passing it something wrapped in check_plain(), we were double escaping, which made events with quotes in the title show up all funny in the message. while i was at it, i added '.' to the end of the messages, as specified here: http://api.drupal.org/api/head/function/drupal_set_message.