please add player ignore lists / killfiles

Feature request: please add a mechanism for ignoring a specified list of other players. This would have the effect of making all their actions completely invisible to you: you don't receive messages from them; nothing they have done shows up in your searches; you don't see their portals, lightposts, crates, or missions; you do not trip their mines; they cannot leave anything on your profile or attach a St. Nick to your character. If the ignored player attempts to interact with you they should receive a notice that you are ignoring them, and they shouldn't lose the tool they tried to use (if any).

I realize that this could take some of the fun out of the game - a player could theoretically ignore almost everyone and thus render themselves immune to mines etc. - but I think you can rely on people to realize that that wouldn't be any fun, and play accordingly. And there *will* be griefers, so we need defenses against them.

Oh, also, to the maximum extent possible, ignore lists should work by *player* instead of *character*, so you can ignore someone and all their sockpuppets go away too.