It can be hard to tell why bitbake does some things slowly. Log the changes
to the base configuration and parse cache status so that it becomes clear
from the logs when the cache invalidation causes a slowdown.
(Bitbake rev: 6e99d89f3c00a5f53c24d687eaef24f52fe0ef99)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>