[developers] compiling rms in sbcl

[Ann Copestake]

This looks much more minor than I'd expected based on your last message and 
it's fine to go ahead with those changes that concern my code.  I think you 
should give oe a chance to look too, though.
That defconstant *coding-system-names* (last point) concerns me a little 
because Allegro CL does warn of redefinitions of constants and I can't find 
where it is defined elsewhere.  defparameter seems like bad style here.  It's 
your code, so if you are having to redefine it for some reason, go ahead, but 
you should check what's happening first. maybe you have it set in a personal 
init file, for instance?

Ann