Require "--" as an argument terminator when running noninteractively
- Require "--" to terminate arguments when running noninteractively.
- Don't correct spelling when running noninteractively (we still suggest corrections).
- Remove old "phage" wrapper script.
- Fix an issue where "argv" could implicitly generate a parseable "--argv" flag.
- Accept "--" as an argument terminator even when there is no argument list.
- Update some strings to use more modern quoting style.
- Make workflows decline to handle signals by default.
- Allow "arc weld" to weld non-UTF8 files together.
Test Plan: Ran various commands. Welded non-UTF8 files.
Maniphest Tasks: T13490
Differential Revision: https://secure.phabricator.com/D21002