Remove the modules and tests that have moved to oslo.log. Replace the
use of oslo.log with the standard library logging module.
Replace calls to LOG.deprecated() with a new function in versionutils
that is copied from the body of the old implementation.
Add fatal_deprecations configuration option to versionutils, where it is
used now instead of the old log module.
Change-Id: I5903f9a9c521789cbf3381d9741a8a5308767e2d
Closes-Bug: #1373120
Blueprint: fix-import-cycle-log-and-versionutils