zstandard: vendor python-zstandard 0.11
The upstream source distribution from PyPI was extracted. Unwanted
files were removed.
The clang-format ignore list was updated to reflect the new source
of files.
The project contains a vendored copy of zstandard 1.3.8. The old
version was 1.3.6. This should result in some minor performance wins.
test-check-py3-compat.t was updated to reflect now-passing tests on
Python 3.8.
Some HTTP tests were updated to reflect new zstd compression output.
# no-check-commit because 3rd party code has different style guidelines
Differential Revision: https://phab.mercurial-scm.org/D6199
#if no-windows no-osx
$ mkdir -p xdgconf/hg
$ echo '[ui]' > xdgconf/hg/hgrc
$ echo 'username = foobar' >> xdgconf/hg/hgrc
$ XDG_CONFIG_HOME="`pwd`/xdgconf" ; export XDG_CONFIG_HOME
$ unset HGRCPATH
$ hg config ui.username 2>/dev/null
foobar
#endif