PDF outline headings, it turns out, should be encoded using either

PDF outline headings, it turns out, should be encoded using either
PDFDocEncoding or UTF-16BE. (The PDF specification's index is
terribly bad; I looked under various obvious things such as
`character set' and `string literal' with no success, and I didn't
manage to find out what character set metadata string literals were
intended to be interpreted in until I discovered from another source
that the encoding was called PDFDocEncoding, and _then_ I was able
to look that up in the index. They should have been using Halibut! :-)

git-svn-id: svn://svn.tartarus.org/sgt/halibut@4101 cda61777-01e9-0310-a592-d414129be87e