Updated setup_boostbook scripts to download newer versions of apache fop
and docbook xsl, since the old versions are no longer posted for download.
The newer version of apache fop is stricter about its input,
and currently fails to validate its input when trying to build boost.pdf,
due to various bits on invalid docbook. I have it working locally
though, and will create tickets with patches in trac for the remaining
issues in the library docs and tools.