Log Message:
lowdown: update to 0.4.1.  From Charlotte Koch.

Push diff implementation (from libdiff) directly into the code instead of using \ 
the external library. From a patch by Anton Lindqvist as suggested on the \ 
OpenBSD ports mailing lits. Thank you!

Significantly update the diffing algorithm. First, make some general fixes to \ 
the algorithm. Second, improve the "optimisations" phase by adding \ 
top-down analysis that matches un-matched, non-terminal adjacent children. This \ 
helps with text changes in text-only paragraphs. Third, add a SES (shortest edit \ 
script) computation for matched adjacent text nodes. Lastly, add the new diff \ 
function manpages.

Portability: don't use %F for date formatting. This doesn't work with some libc \ 
versions. Also some documentation readability improvements.

Strip leading white-space from metadata extracted using -X. Sync with newest \ 
oconfigure.

Document the metadata functionality in lowdown(5), thanks to Christina \ 
Sophonpanich (thanks!). Also sync with newest oconfigure.

Add a "diff" tool, lowdown-diff(1). This utility uses an algorithm \ 
adapted from Detecting Changes in XML Documents to compute the semantic \ 
difference between two parse trees. It is fully documented. While there, also \ 
add more inter-paragraph spacing to -Tms output, producing more elegant \ 
documents, and continue fleshing out lowdown(5). Also add some more metadata \ 
recognition in -s output for all modes (copyright, affiliation, etc.).

Re-wrote escape parser to -Tms and -Tman to respect roff special characters. \ 
Have e-mail autolinks respect the mailto: in pdfhref'd output, and have links \ 
with mailto: omit the schema in display just like in -Thtml. Make \ 
block-list-items render properly in -Tms and -Tman. Also introduce lowdown(5), a \ 
work-in-progress to document the Markdown formatting accepting by this system. \ 
The first were noted, and the last contributed in full, by Christina \ 
Sophonpanich — thanks!

Fixed compilation on Linux and Mac OS X by adding memrchr compatibility. Noted \ 
by Christina Sophonpanich — thanks!

Considerable clean-up of -Tms and -Tman, with the aim of much higher PDF output \ 
quality: proper nested list support, hyperlinks, PS/PDF TOC, and even some \ 
images (PS/EPS only—experimental!). Also, after some pointers on the groff \ 
mailing list, use the correct invocation for generating PDF output. Fix up \ 
footnote printing to use automatic -ms macros and registers, if applicable.

Also added support for the "affiliation" metadata keyword.

Added some CommonMark support, initially just escaped newlines, supported only \ 
when the commonmark input flag is specified. Removed the sphd input flag in \ 
favour of commonmark. Also fixed raw HTML block outputting and setext-style \ 
level-two headers.