Fixes#681. Technically, resending the entire userlist is not
necessary; it would be sufficient to resent setUserMeta, but there's not
currently a bulk frame for that so sending the userlist is probably more
efficient.
User.prototype.refreshAccount was responsible for multiple race
condition bugs as well as inefficient duplication of DB queries in an
attempt to correct such race conditions.
It has now been replaced by a more reasonable model:
* Global user account information and aliases are fetched in parallel
on socket connection
* Channel rank is fetched when the user tries to join a channel
The previous commits do not handle all of the edge cases of #583
appropriately. This is a short term solution that will work, but is not
as efficient as it could be. The whole refreshAccount function needs to
be reconsidered and replaced with a more sane way of handling atomic
updates to the user's account state.
Instead of emitting frames to each individual socket, group them into
socket.io rooms of people who can see hidden poll results and people who
can't, then just do 2 broadcasts.
If clients call it quickly in succession with large playlists, it can
cause node to get stuck stringifying socket.io frames and cause an out
of memory crash.
