UX issues for account preferences when user has multiple emails

[jonathanstegall]

There are some issues I'm realizing we never dealt with when adding multiple email addresses.

1. on /user URL:

If a user has multiple emails on their account, we should tell them which one we're talking about, and possibly give them the ability to switch between them.

2. on user/preferences URL:

Same issue. If a user has multiple emails on their account, we should tell them which one we're talking about, and possibly give them the ability to switch between them.

3. in general:

I'm realizing on both of these URLs, we show the user's preferences if they're unsubscribed. We should show a flag there and give them the ability to resubscribe.