Show progress when evaluating files using `cider-load-all-files`

[katomuso]

Show progress in echo area while recursively evaluating files in directory using cider-load-all-files.

As I've noticed that messages from evaluations keep popping up, so it's very hard to see progress message, I've used inhibit-message around cider-load-file. One possible downside of this is that error messages are not displayed as well (though it will be really hard to notice some error message while messages pop up one after the other).

Also, I've tweaked the prompt of cider-load-all-files because it might not be clear how files are loaded as the word "beneath" is ambiguous (it may mean one level of depth which is not the case).

Closes #3615

[bbatsov]

As I've noticed that messages from evaluations keep popping up, so it's very hard to see progress message, I've used inhibit-message around cider-load-file. One possible downside of this is that error messages are not displayed as well (though it will be really hard to notice some error message while messages pop up one after the other).

Yeah, that's not a big problem - after all most people will get some error buffers anyways.

Just add a changelog entry and we're good to go here.

[katomuso]

I've updated the changelog.

[bbatsov]

Thanks!