Currently, oslo team starts to drop old oslo namespace, the old import
style can work now, but not any more in next development cycle. We've
already done and will continue do the migrate jobs, but we need a way
to prevent accidently import such issue again. The hacking rules cannot
satisfy the need, so let's do the local check.
Code are basically stolen from Nova project.
Note, this patch also fixes some new introduced oslo namespace issues.
Change-Id: I98c81c47a727ed71fb75820f21276cb989d47714