Bug 962320 - Part 1: use per-profile prefs for FxA.
Bug 962299 - Part 3: provide profile when creating an account.
Bug 962320 - Part 2: define DEFAULT_TOKEN_SERVER_URI, rename DEFAULT_AUTH_ENDPOINT -> DEFAULT_TOKEN_SERVER_ENDPOINT.
Bug 962320 - Part 3: thread token server into account.
Bug 962299 - Part 3: provide profile when creating an account. r=nalexander
Bug 962320 - User per-profile prefs for FxA, and store token server in account object. r=nalexander