* mu-cite.el: (char-category): Force redefine as a function because it may
have been defined by emu.el;
don't use `int-char' for XEmacs if the function `char-category-list' returns
a list of characters;
enclose the whole form with `eval-and-compile'.
* MU-CFG: Define the function `add-to-list' for a makeshift.
* MU-MK: Define byte-optimizer for replacing `sref' with `aref';
silence XEmacs not to say "bound but not referenced".
(byte-compile-file-form-custom-declare-variable): Define it for old Emacsen.
* mu-cite.el: Undo the last change.