Have services(/trac) track users by their devhack emails

[m]

Currently trac is using the primary email field which points to people's "real" various emails.

We're actually promoting the opposite right now -- services sending to folks' real emails in various capacities. because we don't have a stable email set up right now.

but maybe one day we will and then funneling everything through our mail server / having the devhack username@… as the standard email info would be cool maybe

Blocking on #732

idk this ticket isn't written in confidence about the direction we want to go in. probably talk to finn and m once the things it's blocking on are done.