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* Support for merging user accounts in client apps.
* i18n using Flask-BabelEx (no UI-facing i18n yet, however).
* Switched to login sessions and cache management (optionally disabled).
* New helper methods owner_choices(), owner_of, member_of in UserBase.
* Login beacon endpoint and object availability as g.lastuser.
* Switch to g.lastuser_cookie for cross-domain login cookie.
* Support for team ownership of resources via helper methods (team, allowner, etc).
* Switch from ~username to username.