* Currently, document::stream contains an attribute that is a reference:
```
document::parser &parser;
```
Yet we try to have it default on the move operator:
```
stream &operator=(document::stream &&other) = default;
stream &operator=(const document::stream &) = delete; // Disallow copying
```
```
stream(document::stream &&other) = default;
stream(const document::stream &) = delete; // Disallow copying
```
I am not sure what the move is supposed to do with the reference.
I cannot find where we test the copy constructor and assignment. This has been concerned that it is either dead code or buggy code.
* Remove non-working, unnecessary move constructors
* We still want to disallow copies.
Co-authored-by: John Keiser <john@johnkeiser.com>
Daniel Lemire