htx: Add PDF to the standard list in the hardcopy server.

Since we're now making PDFs of our documents and will be in 2014A,
enable downloading of PDFs.  Also recommend PDF instead of PostScript
for the graphics content.
htx: Correct PostScript names in hardcopy server.
docs: Improve the html appearance descriptions of the models in SC/21.

Split the model lists in Section 4.3 to LaTeX and html versions to
stop the horrible html formatting.
docs: Fix two issues in the html model descriptions in SC/21.

There was a residual hrule in the htmlonly version, and there was a
missing fullstop at the end of the FLT description.
docs: Adjust position and sizes of a few graphics in SC/21.

After the blue titles were added, the histogram was moved such that
there were two graphics on one page in the LaTeX.
docs: Improved the appearance of Science Pipeline section in SC/21.

Added itemize to Section 9.2 to get rid of asterisks for bullets in
the html.
docs: Use the full jackknife recipe name in SC/21.
docs: Miscellaneous small improvements to SC/21.

Includes updating the document date and adding a recipe
parameter file.