hashconsing 1.6.0

A hash consing library.
Documentation
v1.5.1

- adds `Debug` to hash factories
- hopefully fixed the doc.rs issue, docgen was failing

v1.5.0

- revamped hash-collections, thanks again @alex-ozdemir!

    Details in [PR 8]https://github.com/AdrienChampion/hashconsing/pull/8.

    - pre-`v1.5.0` default was the identity hasher, now called `id-hash`;
    - default hasher is now `p-hash` (faster and deterministic);
    - Rust's std hash (`sip-hash`) also available (non-deterministic);
    - `a-hash` available by activating feature `"with_ahash"` (fastest, non-deterministic).

# Breaking Changes (Kinda)

Previous versions were re-exporting `lazy_static`'s main macro, which was technically not needed. It
has been removed for this version.


v1.3.0

- publicized the weak reference API, thanks @alex-ozdemir!

v1.2.0

- cleaned `lazy_static` re-export, now only re-exporting `lazy_static` macro
- added a `capacity` method on the consign
- added `collect`, `shrink_to_fit`, `collect_to_fit` and `reserve` to the `HashConsign` trait,
    see [issue 2]https://github.com/AdrienChampion/hashconsing/issues/2

# Breaking Changes (Kinda)

Previous versions were exposing too much from `lazy_static` which was a mistake. Only the
`lazy_static` macro is re-exported now, other items such as the `__Deref` trait are not re-exported
anymore.

v1.1.0

- removed systematic unsafe implementations of `Send` and `Sync` for `HConsed`,
    see [issue 1]https://github.com/AdrienChampion/hashconsing/issues/1

v1.0.1

- fixed path bug with `lazy_static` in `consign` macro

v1.0.0

- removed WIP `new_hconsed` macro (I found no way to make it generic enough)
- renamed the factory creation macro `new_consign` to just `consign`

v0.9.11

- more homogeneous struct/trait naming
- documentation effort
- lazy static consign creation macro