Preparing libxslt-0.5.0 while libxml-2.3.4 is uploading:

- configure.in: time for 0.5.0
- tests/docs/Makefile.am tests/general/Makefile.am: make sure the
  new test files are included in the distribution
- doc/xslt.html : updated
- doc/html/*.html: regenerated the docs
Daniel