Code cleanup; Removed unnecessary call to setDownloadStartedFileAttributes
Moved „handleResponse“ method from AFCacheableItem to AFDownloadOperation, split it into smaller parts and cleaned up its code
Moved „fileHandle“ property from AFCacheableItem to AFDownloadOperation
Code cleanup
Fixed priority order for assigning „validUntil“ field; code cleanup
Refactored „validUntil“ calculation to better demonstrate that it results from several different response header fields according to their priority