This pull requests reduces the assumption of a singleton
At a high level, this refactoring was all about replacing the ad-hoc
As an example of a luxury that had to be given up in order to support multiple accounts instances, initialization code that used to run at the top level (like the auto-login code) is now called from the constructor functions.
I think it's now much clearer which methods and properties are available on the client, on the server, or in both places, since each environment has a distinct
Also share urls.* methods between all AccountsServer instances.