Mark the config generator as obsolete

The config generator here is deprecated in favor of the one in
oslo.config.

Change-Id: Ic03a872e27018bdba297497c422caf2904501d5f
Mark oslo.utils modules obsolete

There is now a release of oslo.utils, so we can mark these modules as
obsolete.

Change-Id: I45b61f68d5de2cdab91a0cbb91a09e7f6b9ccecd
Merge "Mark oslo.utils modules obsolete"
Merge "Mark the config generator as obsolete"