* DistUpgrade/DistUpgrade.cfg.dapper, DistUpgrade/prerequists-sources.list.dapper: - add support for dapper->hardy upgrades * DistUpgrade/DistUpgradeConfigParser.py: - add overwrite support for the configuration to support upgrades to multiple target releases with the same upgrader * data/update-manager.schemas.in: - /apps/update-manager/check_dist_upgrades is deprecated * utils/demotions.py: - make it more flexible to support generating both dapper and gutsy demotions