printfing_ostream manipulators copy the ostream & other construction issues

[eyalroz]

Unfortunately, it seems our lambda-based manipulators are implicitly returning a copy of, rather than a reference to, the ostream they got - due to the implicit return type deduction.

In fact, it probably doesn't make much sense to copy-construct printfing-ostreams in the first place. let's disallow that for now. Let's use references or construct explicitly.

Finally, the move-construction of printfing_ostream doesn't initialize most fields from the existing ostream's fields.