Re: -I switch to ls and dired.

[Richard Stallman]

    The reason for this is that dired and dired-aux systematically check
    whether the "R" switch has been used by just checking whether the
    string passed as switches to ls contains _some_ "R" _anywhere_ and if
    for some reason the "R" switch needs to be removed, _all_ R's in the
    string are removed.  Thus the shell pattern `*R* becomes `**' matching
    anything (except `.' and `..' for technical reasons).

    There is no telling what pattern the user might want to ignore with
    -I.  There is no reason why that pattern could not contain "R". 

    What do we do with the above?  Completely ignore it?  Just document
    it?  Fix it?  Fixing it unconditionally might be difficult, but fixing
    it modulo some (to be documented) conventions seems very feasible.

The code that removes -R could be made smarter so that it detects
R as an option, but not R as an argument.  The rules for options
are not that complicated.