Miscellaneous changes, mostly to get PDF building working after I upgraded a load of MacPorts packages :-/

SConstruct:
- Output the PDF to the folder corresponding to its source location.
- Launch the PDF viewer with the absolute path it needs.

docbook45.conf:
- Change biblio entries not to have empty anchors but to use the citetitle element instead.
Not really needed -- was an experiment while looking for the real problem (see below) --
but I decided it was conceptually better anyway.

Discordians-docinfo.in.xml:
- Workaround for the build problem, which was FOP crashing when it failed to hyphenate a URL.
I just re-jigged the text so it doesn't need to be hyphenated.

yaml2svg.rb:
- In passing, add code to skip charm groups which don't have a layout (yet), instead of crashing.