Fixed the Bear's Character (we Re: JCOERCE vs JCAST (was Re: coerce a number to a short))

[As anarchodin notes in discovering that our Unicode normalization has funny spots][1], we need to fix the idea of what a character is in the Java-based Lisp reader. Tis involves doing the right thing at the points in the code where we have comments like // ### BUG: Codepoint conversion [1] https://github.com/armedbear/abcl/issues/146 -- "A screaming comes across the sky. It has happened before but there is nothing to compare to it now."