{{alias}}( oldPath, newPath, clbk )
    Asynchronously renames a file.

    The old path can specify a directory. In this case, the new path must either
    not exist, or it must specify an empty directory.

    The old pathname should not name an ancestor directory of the new pathname.

    If the old path points to the pathname of a file that is not a directory,
    the new path should not point to the pathname of a directory.

    Write access permission is required for both the directory containing the
    old path and the directory containing the new path.

    If the link named by the new path exists, the new path is removed and the
    old path is renamed to the new path. The link named by the new path will
    remain visible to other threads throughout the renaming operation and refer
    to either the file referred to by the new path or to the file referred to by
    the old path before the operation began.

    If the old path and the new path resolve to either the same existing
    directory entry or to different directory entries for the same existing
    file, no action is taken, and no error is returned.

    If the old path points to a pathname of a symbolic link, the symbolic link
    is renamed. If the new path points to a pathname of a symbolic link, the
    symbolic link is removed.

    If a link named by the new path exists and the file's link count becomes 0
    when it is removed and no process has the file open, the space occupied by
    the file is freed and the file is no longer accessible. If one or more
    processes have the file open when the last link is removed, the link is
    removed before the function returns, but the removal of file contents is
    postponed until all references to the file are closed.

    Parameters
    ----------
    oldPath: string|Buffer
        Old path.

    newPath: string|Buffer
        New path.

    clbk: Function
        Callback to invoke upon renaming a file.

    Examples
    --------
    > function done( error ) {
    ...     if ( error ) {
    ...         console.error( error.message );
    ...     }
    ... };
    > {{alias}}( './beep/boop.txt', './beep/foo.txt', done );


{{alias}}.sync( oldPath, newPath )
    Synchronously renames a file.

    Parameters
    ----------
    oldPath: string|Buffer
        Old path.

    newPath: string|Buffer
        New path.

    Returns
    -------
    err: Error|null
        Error object or null.

    Examples
    --------
    > var err = {{alias}}.sync( './beep/boop.txt', './beep/foo.txt' );

    See Also
    --------