A bit of formatting
Refactor slightly
Consistently implement weirdo alignWithTop thing

Also put it in only one place.
Don't create two tails!

Doesn't fix the problem, but wow, really?
Remember to invalidate selectedMessage_

It was causing jumping to bootstrapped things to break horribly.
GREATLY simplify scrollToMessage

Should be possible to simplify some of the other functions this way too. Maybe?
I guess the empty message case is awkward.