Synchronization Improvements

Improvements for all users:

• We introduces automatic error notifications in 3.9.4-beta.1, but a few errors
  were actually not sent. They're effectively sent now.
• Renaming directories a to c then b to a was working for files but not
  for directories. This now works for simple cases. A few complex ones are
  still not working however.
• In some very rare cases where the content of a file in the Cozy doesn't match
  the correct checksum, the app will check the local file version and reupload
  it when relevant.

Improvements for Windows & macOS users:

• When renaming a remote directory by only changing its case, the change was
  applied locally but it was also triggering a weird synchronization loopback
  error. This should now work as expected.

See also known issues.

Happy syncing!