Key changes in this release:
- Update bundled LZ4 library to version 1.7.5
- When version 1.7.5 or later of the LZ4 library is in use we change the default compression level for HC (high_compression) mode to match that of upstream
- Add parameter to lz4.block[de]compress to optionally return bytearray
- lz4.block[de]compress now accept any source object which implements the buffer interface