Structured annotations and documentor XSLT

[Chris Maloney]

I worked for a bit more on the structured annotations, and got them
working pretty well. I wrote up a status report and "still-to-do"
list on issue #3:
https://github.com/NCBITools/DtdAnalyzer/issues/3#issuecomment-9016049.

Audrey, FYI, I hacked your dtddocumentor stylesheet a little bit to
get the auto-linking mechanism to work. I changed the filename format
just a little bit, and so put the filename-generation into a separate
named template called "docFilename".

Note that, unfortunately, if you run the dtdanalyzer with minimal
command-line options against the split example, right now, it will
fail. That's because the comments are in markdown format, and I
changed the default behavior to not use markdown (as described in the
status report I mentioned). So to get it to work, you either have to
install pandoc, and use the "-m" option (the preferred method), or
hack the comments to take out any well-formedness problems. I'm not
too happy with this state of affairs though -- at least we should have
better error reporting.

Let me know what you think.
Cheers!
Chris