Streamable (Mihxil's Math 0.4.0 API)

```
public interface Streamable<T>
```
This interface is missing in java. We use it to mark an AlgebraicStructure as 'countable'. And the (possibly infinite) stream() method would actually do it.

Since:

0.4

Author:

Michiel Meeuwissen

Method Summary

All Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method	Description
`default Stream<T>`	`reverseStream(long first)`	Sometimes it is usefull to be able to produce an 'reversed' stream.
`Stream<T>`	`stream()`

- Method Detail
  - stream
```
Stream<T> stream()
```
  - reverseStream
```
default Stream<T> reverseStream(long first)
```
    Sometimes it is usefull to be able to produce an 'reversed' stream. This default implementation just bases it on stream(), but it may be implementable more efficiently.