System lexbor

Closes #13

See merge request !27

Release 2.2.0

See merge request !25

Bump minimum version to Elixir 1.11 as used by Pleroma

fasthtml_worker: Panic on write(2) failure

See merge request !26

c_src/lexbor: Update to v2.2.0

See merge request !24

Makefile: Obey generic CPPFLAGS/CFLAGS/LDFLAGS from the env.

See merge request !23

Most Linux packaging systems provide generic CPPFLAGS/CFLAGS/LDFLAGS
environement variables that should be used by every package.  These
flags are generic and mostly contain CPU architecture, build
reproducibility and security options.  Not obeying them generally leads
to problems with the package.

Note that CMake does not support CPPFLAGS[1] so we have to coalesce it into
CFLAGS while invoking it.

[1] https://gitlab.kitware.com/cmake/cmake/-/issues/12928

Make repository REUSE compliant

See merge request !22

https://docs.github.com/en/site-policy/github-terms/github-terms-of-service#1-githubs-rights-to-content
> The look and feel of the Website and Service is copyright © GitHub, Inc. All rights reserved. You may not duplicate, copy, or reuse any portion of the HTML/CSS, Javascript, or visual design elements or concepts without express written permission from GitHub.

git diff --name-only 18593ba4..pleroma/master | while read name; do test -e "$name" && reuse addheader --year 2019-2022 --copyright 'Pleroma Authors <https://pleroma.social>' --license 'LGPL-2.1-only' "$name"; done

git ls-tree --name-only -r 18593ba4 | while read name; do test -e "$name" && reuse addheader --year 2017-2019 --copyright 'myhtmlex authors <https://github.com/Overbryd/myhtmlex>' --license 'LGPL-2.1-only' "$name"; done
reuse addheader --year 2017-2019 --copyright 'myhtmlex authors <https://github.com/Overbryd/myhtmlex>' --license 'LGPL-2.1-only' lib/fast_html.ex
reuse addheader --year 2017-2019 --copyright 'myhtmlex authors <https://github.com/Overbryd/myhtmlex>' --license 'LGPL-2.1-only' test/fast_html_test.exs

Update dependencies

See merge request !21

update dependencies

See merge request !20

Fix CI

See merge request !19

update nimblepool to 0.2, update associated callbacks

See merge request !18

submodule ux is garbage lol

remove priv dir to make building work with distillery releases

See merge request !17

Apply gcc-10 bugfix to lexbor

Closes #8

See merge request !16

Fixes: #8

the CI has .git, but not the git executable

again, no version bump because the hex version was republished.

strictly

No version bump since the hex version was just republished as 2.0.1

Not doing that resulted in hexdocs.pm showing an empty svg
instead of the text