Now the `write*` functions for Docbook, HTML, ICML, JATS,
Man, Ms, OPML are sensitive to `writerPreferAscii`. Previously
the to-ascii translation was done in Text.Pandoc.App, and
thus not available to those using the writer functions
directly.
In addition, the LaTeX writer is now sensitive to
`writerPreferAscii` and to `--ascii`. 100% ASCII
output can't be guaranteed, but the writer will use
commands like `\"{a}` and `\l` whenever possible,
to avoid emiting a non-ASCII character.
A new unexported module, Text.Pandoc.Groff, has been
added to store functions used in the different groff-based
writers.
