distributed installations, where the immediate installation location
is different from the final installation location, but in the case
where it is not desirable to put the entire install hierarchy as a
subdirectory of DESTDIR.
only at the time of running the command "load". But cells are generally
loaded only on an as-needed basis, so the dereferencing option must be
saved as a flag in the cell and honored whenever its subcells are expanded
or otherwise read at a later time.