Mozlog currently has two implementations. The top level package is based on the logging module and is
deprecated. The newer structured logging implementation lives in mozlog.structured. This patch swaps the
two, so the top level mozlog module contains the recommended implementation, while mozlog.unstructured
contains the old one.
This removes ambiguity as to which modules are being imported, making
import slightly faster as Python doesn't need to test so many
directories for file presence.
All files should already be using absolute imports because mach command
modules aren't imported to the package they belong to: they instead
belong to the "mach" package. So relative imports shouldn't have been
used.
