Code review comment for lp:~rconradharris/nova/backup_schedule_extension

Thanks for the comments all-- I've updated the patch to reflect the commen

Matt: Yeah, the FLAGS+plugin model has served us really well, don't see a reason why it couldn't work here as well (eventually). As it stands now, though, OS API extensions have their own architecture, and it's probably better--for the time being at least--to be consistent.

This is definitely something we should discuss at the Essex summit: how to rework our extension architecture so it can support truly optional extensions at all layers of the code.