Few new features and support for Chrome Extensions
- Update to hterm 1.78. Extended underlying support.
- Rework label alignment logic.
- Accept URI escapes in usernames & fingerprints.
- Document extensions that whitelist us.
- sftp: document the source a bit more
- Delay some connection dialog work until visibility.
- Unify params object setup.
- Document expected coding style.
- Support running as an extension.