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


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"A screaming comes across the sky.  It has happened before but there is nothing 
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