allow .tac files to configure logging behavior
|Reported by:||radix||Owned by:|
branch-diff, diff-cov, branch-cov, buildbot
It would be useful to allow .tac files to configure logging behavior by specifying in the .tac file the observer to be used.
Of course, twistd should also have some sort of user interface for customizing logging behavior, which is being tracked in #638.