Crate oom

Took inspirations from the "Parse, don’t validate" article.

More introduction is in the README.

Structs

NonEmptyMutSlice	A non-empty mutable slice type, counterpart of &mut [T].
NonEmptySlice	A non-empty slice type, counterpart of &[T].
NonEmptyVec	A non-empty vector type, counterpart of Vec<T>.