Set default log levels for oslo.messaging and oslo-incubator

Add exception to update.py to not rename oslo.messaging, and let
oslo.openstack rename to cover oslo-incubator code.

When debugging a project consuming oslo libs or oslo-incubator they
usually won't have to debug oslo-incubator or oslo.messaging.

Change-Id: Ia12c003dae196e2220a5f6ea768758a75f2ede23