Do not highlight messages containing just a part of the nick
I go by
solid_black on IRC, and Polari notifies me every time someone types "solid".
name_afk and a few other variations should be triggered by typing "name", but it doesn't make sense to treat any nick sub-word appearing in a message as mentioning the user. I dislike configuration options as much as the next guy, but if this can't be deduced automatically, maybe the user should be able to configure which part of their nick is enough for Polari to decide notify them.
This is, in a way, the reverse of #53 (closed).