CHANGELOG: Update entries about EVMC C++ API
- Added: [[#216](https://github.com/ethereum/evmc/pull/216)]
CMake option `EVMC_TEST_TOOLS` to build evmc-vmtester without bothering with internal unit tests.
-- Added: [[#217](https://github.com/ethereum/evmc/pull/217)]
- The `evmc::host` C++ wrapper for EVMC host context and interface
- to be used by VM implementations.
+- Added:
+ [[#217](https://github.com/ethereum/evmc/pull/217)]
+ [[#226](https://github.com/ethereum/evmc/pull/226)]
+ The full C++ EVMC API for both VM and Host implementations.
- Added: [[#201](https://github.com/ethereum/evmc/pull/201), [#202](https://github.com/ethereum/evmc/pull/202), [#233](https://github.com/ethereum/evmc/pull/233)]
Initial and rough bindings for Rust. It is possible to implement an
EVMC VM in Rust utilising some helpers.
[[#230](https://github.com/ethereum/evmc/pull/230)]
[[#232](https://github.com/ethereum/evmc/pull/232)]
Handling of DLL loading errors greatly improved by `evmc_last_error_msg()` function.
+- Changed: [[#195](https://github.com/ethereum/evmc/pull/195)]
+ The minimum supported GCC version is 6 (bumped from undocumented version 4.8).
- Changed: [[#197](https://github.com/ethereum/evmc/pull/197)]
Go bindings improved by introduction of the `TxContext` struct.
- Changed:
