Weird behaviour of cohttp-lwt-unix logging

[mseri]

This can be seen from the server:

$ cohttp-server-lwt
[DEBUG][application]: Cohttp debugging output is active

$ cohttp-server-lwt --verbose
[DEBUG][application]: Cohttp debugging output is active
[INFO][cohttp.lwt.server]: Listening for HTTP request on: :: 8080

Without the verbose flag I would expect just the info to appear, instead the debug message appears always while the info message only when we use the verbose flag.

I also think that we should make the verbose output more verbose, more like python's http.server:

$ python -m http.server
Serving HTTP on :: port 8000 (http://[::]:8000/) ...
::ffff:127.0.0.1 - - [14/Apr/2021 21:24:04] "GET / HTTP/1.1" 200 -
::ffff:127.0.0.1 - - [14/Apr/2021 21:24:04] code 404, message File not found
::ffff:127.0.0.1 - - [14/Apr/2021 21:24:04] "GET /favicon.ico HTTP/1.1" 404 -
::ffff:127.0.0.1 - - [14/Apr/2021 21:24:06] "GET /bin/ HTTP/1.1" 200 -
::ffff:127.0.0.1 - - [14/Apr/2021 21:24:07] "GET /bin/lib.ml HTTP/1.1" 200 -

[mseri]

We should probably deal with it when we deal with #645

[mseri]

Closing since most of it has been improved by #772.
We can open a new issue if other people are unhappy with the current quiet logging