The first suggestion to allow /unignore offline player is denied, it does not make any difference as you wont be seeing his msg if he's offline and you can easily unignore him when he's online if you wish to see his msg. But i have added /unignore all instead.
Personally, i dont plan to make server saves ignore list at all. I think it's better to keep them temporarily until player disconnect from server. The ignore cmd is supposed to be used when player insult you and only when he does so, besides it's really easy to use the cmd, so keeping such thing in database is seen as a waste of space. But as it's already implemented like that, i will just keep it that way.