Support unordered and ordered lists with "fragment" elements.
Modified by JGM to remove the --reveal_js-url command-line option.
Instead use -V reveal_js-url=... as with slidy and the other slide
formats. Also cleaned up the list code in the HTML writer.
The template redefines `\includegraphics` to give special treatment
for too-wide images. But this causes problems for literal uses
of `\includegraphics`. This change allows authors to use
`\Oldincludegraphics`, as in the latex template.
* RTF writer: Export writeRTFWithEmbeddedImages instead of
rtfEmbedImage.
* Text.Pandoc: Use writeRTFWithEmbeddedImages for RTF.
* Moved code for embedding images in RTF out of pandoc.hs.
The previous default was to use `<q>` tags in HTML5.
But `<q>` tags are also valid HTML4, and they are not very
robust in HTML5. Some user agents don't support them,
and some CSS resets prevent pandoc's quotes CSS from working
properly (e.g. bootstrap). It seems a better default just
to insert quote characters, but the option is provided for
those who have gotten used to using `<q>` tags.
