Expose the complete click API

[ulope]

Currently only some of the click namespace is re-exported by cloup.

That makes it somewhat annoying to upgrade a click project because a simple import cloup as click doesn't work (since for example echo, prompt and others aren't being exported).

[janluke]

This was actually a deliberate choice, but I'm now reconsidering it.

Note that for type checking reasons, I can't just put from click import * in cloup __init__.py; the symbols to export must be listed explicitly, which means they can get out of sync with click, and there might also be problems when supporting multiple versions of click.

I opened a draft PR (#205). I'd appreciate your feedback on this issue/PR, @kdeldycke.

[kdeldycke]

That's already what I do in Click Extra: I overwrite all Click imports by Cloup, then I add mine. See: https://github.com/kdeldycke/click-extra/blob/8f723721d48bc6132177f03d40789b297ca3e757/click_extra/__init__.py#L37-L38

So all in all, I'm in favor! :)

[kdeldycke]

If you want to make from cloup import * a drop-in for click, beware that you have _version and warnings in src/cloup/__init__.py that looks like unwanted imports side-effects. And warnings is not the one from the Python stdlib but Cloup's specifics.