avoid pacman output to console unless debug
log to journal even if invoked from command-line
removed unused code
introduced AbstractBackup supertype
Refactored backup with callback, so it is independent of using Zip
backup API is now relative to bucket, not relative to a constructed path; much more flexible
partial siteIds now need to have trailing ...
avoid creation of backup zip files during upgrades or redeploys
removed BackupManager classes; no more point
do not backup before undeploy; user needs to do that
bug fixes in CreateSite