message: Add CHANGELOG entry for [skip ci]
diff: @@ -112,11 +112,34 @@ and this project adheres to
  API provided by the VM's backend (i.e. the blockchain).
  - contracts: `reflect` contract requires `stargate` feature and supports
  redispatching `Stargate` and `IbcMsg::Transfer` messages ([#692])
  +- cosmwasm-std: The arithmetic methods of `Uint128` got a huge overhaul, making
  + them more consistent with the bahaviour of the Rust primitive types. Thank you
  + [@yihuang] for bringing this up and for the great implementation. ([#853])
  + 1. `Uint128` got the new functions `checked_add`, `checked_sub`,
  + `checked_mul`, `checked_div`, `checked_div_euclid`, `checked_rem`,
  + `wrapping_add`, `wrapping_sub`, `wrapping_mul`, `wrapping_pow`,
  + `saturating_add`, `saturating_sub`, `saturating_mul` and `saturating_pow`
  + which match their equivalent in [u128] except that instead of `Option` the
  + checked methods return a `Result` with an `OverflowError` or
  + `DivideByZeroError` that carries a few debug information and can directly
  + be converted to `StdError`/`StdResult` by using the `?` operator.
  + 2. `StdError::Underflow` and `StdError::underflow` were removed in favour of
  + `StdError::Overflow`. `StdError::DivideByZeroError` was added.
  + 3. The `-` operator (`impl ops::Sub<Uint128> for Uint128`) was removed
  + because it returned a `StdResult` instead of panicking in the case of an
  + overflow. This behaviour was inconsistent with `+` and the Rust standard
  + library. Please use the explicit `*_sub` methods introduced above. In a
  + couple of releases from now, we want to introduce the operator again with
  + panicking overflow behaviour ([#858]).
  [#696]: https://github.com/CosmWasm/cosmwasm/issues/696
  [#697]: https://github.com/CosmWasm/cosmwasm/issues/697
  [#736]: https://github.com/CosmWasm/cosmwasm/pull/736
  [#690]: https://github.com/CosmWasm/cosmwasm/issues/690
  +[@yihuang]: https://github.com/yihuang
  +[#853]: https://github.com/CosmWasm/cosmwasm/pull/853
  +[#858]: https://github.com/CosmWasm/cosmwasm/issues/858
  +[u128]: https://doc.rust-lang.org/std/primitive.u128.html
  ### Deprecated
  