* Require recent doctemplates. It is more flexible and
supports partials.
* Changed type of writerTemplate to Maybe Template instead
of Maybe String.
* Remove code from the LaTeX, Docbook, and JATS writers that looked in
the template for strings to determine whether it is a book or an
article, or whether csquotes is used. This was always kludgy and
unreliable. To use csquotes for LaTeX, set `csquotes` in your
variables or metadata. It is no longer sufficient to put
`\usepackage{csquotes}` in your template or header includes.
To specify a book style, use the `documentclass` variable or
`--top-level-division`.
* Change template code to use new API for doctemplates.
* XML.toEntities: changed type to Text -> Text.
* Shared.tabFilter -- fixed so it strips out CRs as before.
* Modified writers to take Text.
* Updated tests, benchmarks, trypandoc.
[API change]
Closes#3731.
