Allow sorting player list on IRC by plain name

Before (list-sort-by-name: false):
![Before, sorted by prefix code](http://i.imgur.com/ukC8oSl.png "Before, sorted by prefix code")

After (list-sort-by-name: true):
![After, sorted by name](http://i.imgur.com/Ez5HlTN.png "After, sorted by name")