* Fix IntegrationCommandTestCask

Fix exit code for multilingual cask audit.

Change `A Cask for #{token} is already installed.` message.

Add `.com.apple.timemachine.supported` to DMG_METADATA_FILES.

virtualenvs remember the prefix of the python that created them and do
magic to load packages from them; help them remember a more durable
path.

Refactor Cask’s extensions.

Use `module_function` for `Homebrew` module.

brew.sh: don't autoupdate if --help passed

fix tests failing when verbose set

Formula-Cookbook: fix /usr/local/Homebrew references.

virtualenv_install_with_resources: select correct python

Make `MacOS.language` less opinionated and add `language` stanza.

`virtualenv_install_with_resources` will now attempt to guess the
desired Python based on the active build options and based on the
dependencies and requirements. When the situation is ambiguous (e.g.,
`depends_on :python3` and `build.with? "python"` is true) raise
`FormulaAmbiguousPythonError` unless `:using => "python"` or
`:using => "python3"` has been passed to resolve the ambiguity.

In most cases, this will allow

```
    virtualenv_create(libexec, "python3")
    virtualenv_install_with_resources
```

to be changed to just

```
    virtualenv_install_with_resources
```

Add official external commands to manpage.

*/diagnostic: tweak messaging.