Back out my earlier change. Note that this is just for the 1.1.5R floppies;
the 1.1.5A ones still have the work-around method (which works fine and
doesn't hurt anything, it's just kludge!).
called `-' lying around on the users system forever) login shells will fail.
Just special-case the handling of `-' for now until/unless I find a more
palatable solution.
