Reset version numbers on document move

Improvements for all users:

• We keep track of the changes made to documents to synchronise either with the
  remote Cozy or the local filesystem using version numbers for each side of the
  synchronisation. When moving a document, be it either a directory or a file,
  on the local filesystem as part of its parent directory move, the new local
  version number would be false, resulting in a possible desynchronisation of
  content updates.
  We now make sure both the local and remote version numbers get resetted in
  this situation so future updates will be synchronised in the right direction.

Happy syncing!