Case sensitivity (was: CLtL, cleanups)

[barmar@Think.COM (Barry Margolin)]

I found a better function than SI:RDTBL-TRANS.  There's a *documented*
function SET-CHARACTER-TRANSLATION.  The calling sequence is

set-character-translation from-char &optional (to-char nil) (readtable *readtable*)

If to-char is NIL then the character isn't translated.  So, to get
case-sensitive reading, do

	(loop for code from (char-code #\a) to (char-code #\z)
	      do (set-character-translation (code-char code)))

This function also does some sanity checking that SETF of SI:RDTBL-TRANS
bypasses; for instance, it won't let you set the translation of a
readmacro character (except to set it to translate to itself).

                                                barmar