1. Add a version history
2. Update copyright years across the code base
3. Run format_all.sh
4. Update version strings from 2.1.0 to 2.2.0 in the docs and
elsewhere.
Change-Id: I46d8d479d54bd6002d532785e67342106e73c9ac
This is mostly just applying the existing clang format config, except:
- Use NOLINT on overlong comment lines.
- Wrap some sections in 'clang-format off' / 'clang format on'.
- Manually split or join some multi-line strings.
Change-Id: Ia1a40eeb92112e12c3a169309afe087af55b2f4f