fix: implement missing shrinks for standard adhocracy types
fix: shrink for Scripts

actually, there were two bugs:

 (1) the integer that path refs were compared against were not the
serial numbers, but the helper indices created locally in this function.
  stupid.

 (2) there were loops, because rs' was constructed to drop dangling
references immediately, thus shortening the output list and running into
unconstructed parts when checking for more dangles.  slightly less
stupid, and much more fun.  (:
Test.Story: fix (incomplete): proper treatment for root path references.  new type for path references.