fixes bug #97950 for cdata-section-elements checks in recursive copies.

* libxslt/transform.c: fixes bug #97950 for cdata-section-elements
  checks in recursive copies.
* tests/docs/Makefile.am tests/docs/bug-96.xml
  tests/general/Makefile.am tests/general/bug-96.*: added the
  example in the regression tests for this case
Daniel