config('key') returns a difficult object

[Stuart Bishop]

The Serializable class returned by config() needs work. In particular, it doesn't implement __str__ allowing it to be used in string contexts like 'subprocess.check_call(['cmd', config('foo')])' or __nonzero__ allowing it to be used in boolean contexts like 'if config('foo'):'

[Stuart Bishop (stub)]

Real problem here is that Serializable can only wrap dictionaries, and was being used to wrap string results (the juju helpers return single strings if there is a scope, or a dictionary of the whole dataset).

[Stuart Bishop (stub)]

Well, it *can* wrap other objects, but they are then broken. eg. Serializable('a')[0] explodes