Add 0.9.3 and fix control
Merge pull request #4987

0866948 Add 0.9.3 and fix control (Matt Corallo)
doc: Update SHA256SUMS.asc step in release-process.md

- The Hash: header is prepended by gpg, and states the hashing used by
  gpg, not what is used to hash the files

- Add more detailed steps