Default Bounds stream to None

[philippjfr]

Any arbitrary default values are unlikely to really make sense and Bounds should also allow None in other cases.

[jlstevens]

Any arbitrary default values are unlikely to really make sense

Well, I already made use of these values in a Bounds stream I used - my code snapped to the nearest available key which meant any value would do.

I also have a vague memory of the default of NumericTuple being specified as None actually becomes (None, None) or a similar tuple of the specified length. If that is true, then the length should be specified as four and the default is really (None,None,None,None).

I might be wrong but this is worth checking. If it really is None, I can merge and then update the code that made use of this default value.

[philippjfr]

It really is None.

[jlstevens]

Must be remembering an old param bug then. Merging.