Update REWORD for UNSET! locals
Update REWORD for UNSET! locals

The REWORD function hadn't been updated to the new invariant of
function locals being unset by default, and @BrianH tended to like
taking advantage of that.  Also reformats to make it flow a little
more and restores CASE to lib/case by moving the refinement out of
the way.

giuliolunati/ren-c,draegtun/ren-c,codebybrett/ren-c,codebybrett/ren-c,hostilefork/rebol,rgchris/ren-c,hostilefork/rebol,rgchris/ren-c,kealist/ren-c,giuliolunati/ren-c,kealist/ren-c,kealist/ren-c,draegtun/ren-c,hostilefork/rebol,hostilefork/rebol,giuliolunati/ren-c,draegtun/ren-c,giuliolunati/ren-c,rgchris/ren-c,hostilefork/rebol,codebybrett/ren-c,draegtun/ren-c,kealist/ren-c,rgchris/ren-c,codebybrett/ren-c,kealist/ren-c,kealist/ren-c,draegtun/ren-c,rgchris/ren-c,draegtun/ren-c,codebybrett/ren-c,giuliolunati/ren-c,hostilefork/rebol,codebybrett/ren-c