[oe] Bitbake task logging

[Esben Haabendal]

> e) I'm not 100% on this yet but I'm wondering if we should scrap
> stdout/stderr output to the UI console in debug mode, just make it clear
> where the output went on the console? If you ever have two tasks running
> the output is unreadable anyway.

Yes, stdout/stderr from two (or more) concurrent tasks are pretty
unreadable at best.  But it could make sense to have a debug mode which
does output stdout/stderr to console, while disabling concurrent task
execution.

/Esben