brew-update: show upgrade command on formula parameters.

Closes #17814.
Add 'brew reinstall' command.
brew-doctor: fix autocrlf warning (again).

Closes #17843.
brew-create: don't insert autodetected versions.
Rework brew command dispatch order.

Make it no longer possible to override e.g. `brew install` with a
script if there is already a built-in Homebrew command named
`brew install`.

References #17673
Rename Library/Contributions/cmds -> cmd.