integer-iterator

Implement Iterator over primitive integer types in Rust. Also, this crate exposes the trait so one can implement it for any desired types.

Examples

```rust let mut positive = 1234u32.digits(); asserteq!(positive.next(), Some(4)); asserteq!(positive.next(), Some(3)); asserteq!(positive.next(), Some(2)); asserteq!(positive.next(), Some(1));

let mut negative = (-1234i32).digits();
assert_eq!(negative.next(), Some(4));
assert_eq!(negative.next(), Some(3));
assert_eq!(negative.next(), Some(2));
assert_eq!(negative.next(), Some(1));

```