Add a verbose and debug mode to parcel for better bug reports

[DeMoorJasper]

This PR adds 2 extra log modes, one verbose mode and debug mode

This way we can just ask to submit their build (debug) log to a bug report in case it's a private project

It will also help with debugging for anyone looking into the issues

logLevel 4 => Verbose
logLevel 5 => Debug/Log mode (creates a log file per build)

Debug log format: parcel-debug-yyyy-mm-dd@hh:mm:ss.log
Verbose line format: [timestamp]: ...

Closes #993 Closes #1527
Related issue, that might benefit from this debug mode: #1331

[devongovett]

This would probably be useful, but I'm a little worried about performance of all of these extra function calls when it is not enabled. Did you do any perf testing?

[tmchng]

@devongovett Honestly I think right now parcel should focus on getting rid of critical bugs first (like #1331).

This PR will be much needed so that people like myself who come across blocking bugs can help out more easily. Performance can come later, and users like myself can wait.

Parcel is a great tool, and it's frustrating that I now need to go back to webpack again due to random freezes.

[kjellski]

@devongovett I think @tmchng is right. We currently have absolutely no option to provide information on why the tool is breaking our builds. For me it suddenly hangs somewhere and then we're done. No way to find out. Going back to webpack seems the only way out currently...

And that's really sad, honestly... I'd like to help, but I can't.

[DeMoorJasper]

Please move discussion to #1834 or open a new issue

[DeMoorJasper]

@kjellski Might be related to sass if you're using that, see #1847

Feel free to hit me up on https://spectrum.chat/parcel if you need any help debugging or fixing the issue