Re: Quiet re-imports

[Diego]

> Diego's issue is that there's no way to make csi to not import scheme by 
> default. So adding a flag for that would solve the issue.

More specifically, the issue is that it imports scheme, chicken.base, and 
chicken.syntax by default. If there was a way to entirely disable the default 
imports that would be useful. But this happens both at the csi level and at the 
`eval` level, so it might be a bit tricky.

There's a bit more to it, I think - the issue also affects the behavior of eval 
in compiled code, even when passing -explicit-use - it still has access to 
bindings in those default imports. It also is still able to e.g. eval `print` 
inside a module with only `scheme` imported.

Additionally, maybe relatedly, using -explicit-use still lets you use 
chicken.base macros like assert, which is behavior I wouldn't expect.

> Do you have some other cases in mind where it's not possible to avoid these 
> warnings?

I think csi usage is the main use-case, since `csi -s` and compiled code don't 
seem to issue these warnings. I'd still argue it'd be nice to have some 
optional flag to quiet the warnings just for interactive/REPL use. Or maybe 
(import-quiet ...) or something.