axzshctl: Enhance activation of "foreign" modules
axzshctl: Enhance activation of "foreign" modules

- Name foreign code "modules", as we don't know yet if it provides a
  theme or a plugin.
- Don't enable it as a plugin when a theme is provided (in this case,
  enable it as a theme only).
- Check for a theme not only on initial cloning, but on all activations.

alexbarton/ax-zsh