* UpdateManager/Core/MetaRelease.py: - remove debug message (LP: #310046) * UpdateManager/Common/utils.py: - when initializing the proxy configuration, do in this order: * check apt setting * check synaptic setting * check users gconf * check http_proxy environment (LP: #24250) * UpdateManager/Core/DistUpgradeFetcherCore.py: - ensure correct error message if downloading failed (LP: #113658) - when fetching from mirrors, add fallback if the mirror is too loaded to cope - improve logic that detects what mirror is in use by sources.list inspection (LP: #107983) * DistUpgrade/DistUpgradeMain.py, dist-upgrade.py: - re-factor and make code more modular - do not overwrite existing log files on upgrade (LP: #111819) * reorganize the imports and get rid of "Common" submodule and merge that all into "Core" * improve the debug output via the "DEBUG_UPDATE_MANAGER" environment