shadowed rel_ops operators

[Richard Andrews]

> > A cursory examination suggests that the inclusions are just an 
> > inheritance from the SGI STL, in support of compilers that fail to
> > implement template overloading.  It appears that the includes can, 
> > and should, be eliminated.  Once they are eliminated, we can also 
> > add a #warning to stl_relops.h.
> 
> Well, we can't take them out of std_utility.h.  Removing the includes from
> the others sounds good, though.
> 
> Any suggestions for the text of the #warning?


"warning : rel_ops may interfere with parts of standard library. See $(documentation) for details."


I'm sure we've only seen a small fraction of the areas rel_ops can interfere with. 
Maybe there should be a section in a FAQ or info page somewhere dedicated to known conflicts.