Function silc_sftp_rename
SYNOPSIS
void silc_sftp_rename(SilcSFTP sftp,
const char *oldname,
const char *newname,
SilcSFTPStatusCallback callback,
void *context);
DESCRIPTION
Renames a file indicated by the `oldname' to the name `newname'. The
`callback' is called to indicate the status of the renaming.