Add option to customize log format

[syndicut]

Allows customizing the default %(asctime)s %(levelname)s %(message)s format to something different. Can be useful for getting JSON format logs, for example.

[syndicut]

@mnaberez any chances this could be merged?

[rootVIII]

Has this been added? All I want to do is change msecs to use a period instead of a comma.

[syndicut]

@mnaberez Is there any way I can help to merge this PR?

[bdellegrazie]

@mnaberez This has been approved, can it be merged?

[mnaberez]

This has been approved, can it be merged?

The individual who has approved this is not a developer on this project (on GitHub, anyone can hit the approve button). I've been @-mentioned here several times but I haven't actually looked at this, sorry. If one of the other developers with commit access approves it, they can just merge it. I'm currently working on other issues.

[LVladymyr]

Guys, it looks like cool functionality. And it wait for your validation.
@JensRantil @msabramo @gcarothers

[dhoppmann]

This is a great feature, I can't wait for it to be merged!