Todo
  * Make a test suite which can run on all the given types of fs
  * Copy should use the sync code as it is more efficient at directory listing
  * FIXME: ls without an argument for buckets/containers?
  * FIXME: More -dry-run checks for object transfer
  * Might be quicker to check md5sums first? for swift <-> swift certainly, and maybe for small files
  * swift: Ignoring the pseudo directories
    * if object.PseudoDirectory {
      * fmt.Printf("%9s %19s %s\n", "Directory", "-", fs.Remote())
  * Make Account wrapper
    * limit bandwidth for a pool of all individual connectinos
    * do timeouts by setting a limit, seeing whether io has happened
      and resetting it if it has
    * make Account do progress meter
  * Make logging controllable with flags (mostly done)
  * -timeout: Make all timeouts be settable with command line parameters
  * Check the locking in swift module!
  * Windows paths? Do we need to translate / and \?
  * Make a fs.Errorf and count errors and log them at a different level
  * Add max object size to fs metadata - 5GB for swift, infinite for local, ? for s3
    * tie into -max-size flag

Ideas
  * could do encryption - put IV into metadata?
  * optimise remote copy container to another container using remote
    copy if local is same as remote - use an optional Copier interface
  * Allow subpaths container:/sub/path
  * support
      * sftp
      * scp
      * Google cloud storage: https://developers.google.com/storage/
      * rsync over ssh
      * dropbox: https://github.com/nickoneill/go-dropbox (no MD5s)
  * control times sync (which is slow) with -a --archive flag?

Need to make directory objects otherwise can't upload an empty directory
  * Or could upload empty directories only?
  * Can't purge a local filesystem because it leaves the directories behind

s3
  * Can maybe set last modified?
    * https://forums.aws.amazon.com/message.jspa?messageID=214062
    * Otherwise can set metadata
  * Returns etag and last modified in bucket list

Drive
  * Should keep a note of files we list then call a new method
    Object.Update() which would be more efficient than haveing to look
    the id up for each file
 
Bugs
  * Non verbose - not sure number transferred got counted up? CHECK