Ebookmaker

- added rendering for <q>: ebookmaker will now change all <q> tags to <span> for epub builds, keeping any attributes on the tags. curly quotes will be added inside the spans, double for top level q and single for all q nest in other qs.

- corrected text in PG footer for RST - thanks Roger Frank. Note that boilerplate generation is being revised for v0.11
- when reflowing pre, don't make it one long line. This was causing problems in the Kobo reader.
- don't drop a heading that starts with "by " if class 'x-ebookmaker-important' is on it.
- also log headings that are dropped because they start with "by "
- fix bug in anchor fixing where if an <a> tag had both id and name attributes, both were deleted.
- delinting

- fixed minor issue where "too deep" errors were emitted for self-links. Thanks to rfrank for the error report.
- fixed deprecation warning from Docutils; should be ok for Docutils > 0.1

- SVG files are now considered images and included in EPUBs. They were being discarded. SVG files are not scaled or compressed by ebookmaker - the renderer should be able to auto-scale. This appears to fix kindlegen failures associated with svg images.
- fixed the rst test

- changed font for rst conversion. Linux Libertine was unmaintained since 2012 and no package was available for CENTOS8. We switched to the closest replacement, Libertinus https://github.com/alerque/libertinus
- added documentation about configuration for rst conversion
- the deprecated 'handheld' media query was being used to prevent ebookmaker from stripping floats. to preserve this feature, ebookmaker no longer strips floats when the css selector contains the x-ebookmaker class. Most likely, float stripping was originally needed because html pages were designed before the advent of EPUB. Today, we can assume that if the html designer uses the x-ebookmaker class, they've considered the impact of the float on the generated EPUB.
- assorted delinting

- added 'x-ebookmaker' class to epub body elements. There are now 4 "x-ebookmaker" classes
- css can now apply styles that are triggered by being a descendent of .x-ebookmaker. This addition is meant to replace the 'handheld' media query that is deprecated in HTML 5
- the 'x-ebookmaker-important' class on on image element tells ebookmaker not to remove the image, even in no-images builds.
- the 'x-ebookmaker-drop' class tells ebookmaker to remove an element and its descendents from ebook builds.
- the 'x-ebookmaker-pageno' class is applied to some span elements whose content has been stripped because they use a class that indicates they represent page numbers: pagenum pageno page pb folionum foliono
- added mayan as a language not supported by kindlegen
- typos fixed in README - thanks Joseph Koshy