This was intended to provide a mechanism to remove old files from an enduser's cache, where version number updates result in files which will never be seen.
deleteOldVersions( ) → void [view source]find aggregations within the user's history. This currently looks for $Y, but aggregations can also be $y, etc.
Return an array of files where newer versions prevent the older from being used. This will not look for version constraints (e.g. $(v,lt=2)), so use with some care.