FR: Split loggers between stdout and stderr

[tvogel]

Because I am using vdirsyncer together with https://habilis.net/cronic/ from cron, it would be better if only real errors (and maybe warnings) would get logged to stderr but not INFO messages such as "Syncing <calendar_name>". Because them getting sent to stderr makes cronic (justifiably) interpret them as an error.

I found an example how you might be able to implement that easily: https://stackoverflow.com/a/16066513/119725

• vdirsyncer version: 0.18.0
• Python version: 3.9.15
• operating system: Linux 3.10.0-1160.53.1.el7.x86_64
• config file: n/a

[WhyNotHugo]

Not a bad idea, we currently don't print anything to stdout anyway.

[WhyNotHugo]

Overriding the default logger configuration sounds like a reasonable approach for this.