message: storage: deprecate Iter
  The iterator does not seem to get much use and its implementation
  is better folded into a more performant reimplementation of
  the Range iterator.
diff: @@ -74,6 +74,7 @@ impl<'a> Iterator for IteratorType<'a> {
  }
  }
  +#[deprecated]
  pub struct Iter<'a> {
  storage: &'a Storage,
  @@ -87,7 +88,9 @@ pub struct Iter<'a> {
  iterator: IteratorType<'a>
  }
  +#[allow(deprecated)]
  impl<'a> Iter<'a> {
  + #[deprecated]
  pub fn new<H>(
  storage: &'a Storage,
  from: H,
  @@ -135,6 +138,8 @@ impl<'a> Iter<'a> {
  Ok(iter)
  }
  }
  +
  +#[allow(deprecated)]
  impl<'a> Iterator for Iter<'a> {
  type Item = Result<(RawBlock, Block)>;
  