capnslog: Capnslog should default to using stdlib "log"

[bobbyrullo]

This way, people who import libraries which use capnslog but don't explicitly set it up still get logging.

[bobbyrullo]

This turns out to be very important even in situations where you DO set up capnslog in your main module: testing. Unless you specifically set up capnslog in your test code, it will silently swallow all logs, making it hard to debug stuff.

[jonboulle]

@bobbyrullo is this fixed by #28?

[bobbyrullo]

It seems to. I'll have to try it out to make sure.

[bobbyrullo]

It's not fixed. Sorry for not trying it out before, but it still swallows messages when no formatter has been set.

[bobbyrullo]

Feel free to reprioritize this - I thought it was swallowing errors from tests, which it is not (that would've been a p0), but it still swallows messages from the rest of the app. I'll take a look and see if I can do a quick fix.

[purpleidea]

Not sure if this issue is related to: etcd-io/etcd#4115 (comment)