
  -spec make_symlink(Existing, New) -> ok | {error, Reason}
                        when
                            Existing :: name_all(),
                            New :: name_all(),
                            Reason :: posix() | badarg.

  Creates a symbolic link New to the file or directory Existing
  on platforms supporting symbolic links (most Unix systems and
  Windows, beginning with Vista). Existing does not need to exist.
  Returns ok if the link is successfully created, otherwise 
  {error, Reason}. On platforms not supporting symbolic links, 
  {error, enotsup} is returned.

  Typical error reasons:

  eacces:
    Missing read or write permissions for the parent directories
    of Existing or New.

  eexist:
    New already exists.

  enotsup:
    Symbolic links are not supported on this platform.

  eperm:
    User does not have privileges to create symbolic links (
    SeCreateSymbolicLinkPrivilege on Windows).
