If there's a conflict, have the Dropbox server try to
autorename the file to avoid the conflict.
allow_ownership_transfer
Allow moves by owner even if it would result
in an ownership transfer for the content being moved. This does not apply
to copies. The default for this field is False.
verbose
By default verbose output is FALSE. Set to TRUE
if you need to troubleshoot any output or grab additional parameters.
dtoken
The Dropbox token generated by drop_auth. rdrop2
will try to automatically locate your local credential cache and use them.
However, if the credentials are not found, the function will initiate a new
authentication request. You can override this in drop_auth by
pointing to a different location where your credentials are stored.