v1.200

Changes:

• Add versioning to the generated config. This will allow to detect dangerous attempts at downgrading to an older version of github-keygen.
• Preserve the position of the github-keygen section in ~/.ssh/config. Previously, the section was always put at the end of the file. This was breaking configs were the user had a Host * section at the end of the file to set default settings: as the section was moved above us, those default settings were applied before our own.