This function will remove a directory on the remote server, if
possible. Once the remove is complete, the Done callback will be
invoked. If no error occurs, the ErrorCode argument in the Done callback will be set
to 0 (zero). If an error occurs, ErrorCode will hold the number of the error and
ErrorText will contain a description
of the error.
If the remote directory contains files or subdirectories -
it is possible (and the most common behavior) that you will
be not be able to remove it. This depends on the server's implementation of
this command.
No wildcards can be used for the RemotePath argument. The RFC protocol specification
for SFTP does not allow them.
