Added observer for iCloud download notifications in Idiomatic for iOS. Now triggers a sync.
Changed handling of data files. It was possible for a race condition to arise where files were deleted prematurely, because the event they belong to had not yet been imported.
Now, when they are downloaded, data blobs get put in a newdata directory. They won't get deleted from that unless the file is removed remotely.
When the content of a new file actually gets referenced by an event, the file is moved to the 'data' folder, and from then on, it is eligible for removal should all events referencing it be removed.