hooks: introduce a `:run-with-plain` option for hooks This option control if HGPLAIN should be set or not for the hooks. This is the first step to give user some control of the HGPLAIN setting for they hooks. Some hooks (eg: consistency checking) deserve to be run with HGPLAIN, some other (eg: user set visual helper) might need to respect the user config and setting. So both usage are valid and we need to restore the ability to run -without- HGPLAIN that got lost in Mercurial 5.7. This does not offer a way to restore the pre-5.7 behavior yet (respect whatever HGPLAIN setting from the shell), this will be dealt with in the next changeset. The option name is a bit verbose because implementing this highlighs the need for another option: `:run-if-plain`. That would make it possible for some hooks to be easily disabled if HG PLAIN is set. However such option would be a new feature, not something introduced to mitigate a behavior change introduced in 5.7, so the `:run-if-plain` option belong to the default branch and is not part of this series. Differential Revision: https://phab.mercurial-scm.org/D9981

syntax: glob

*.elc
*.tmp
*.orig
*.rej
*~
*.mergebackup
*.o
*.so
*.dll
*.exe
*.pyd
*.pyc
*.pyo
*$py.class
*.swp
*.prof
*.zip
\#*\#
.\#*
tests/artifacts/cache/big-file-churn.hg
tests/.coverage*
tests/.testtimes*
tests/.hypothesis
tests/hypothesis-generated
tests/annotated
tests/exceptions
tests/python3
tests/*.err
tests/htmlcov
build
contrib/chg/chg
contrib/hgsh/hgsh
contrib/vagrant/.vagrant
dist
packages
doc/common.txt
doc/*.[0-9]
doc/*.[0-9].txt
doc/*.[0-9].gendoc.txt
doc/*.[0-9].{x,ht}ml
MANIFEST
MANIFEST.in
patches
mercurial/__modulepolicy__.py
mercurial/__version__.py
mercurial/hgpythonlib.h
mercurial.egg-info
.DS_Store
tags
cscope.*
.vscode/*
.idea/*
.asv/*
.pytype/*
.mypy_cache
i18n/hg.pot
locale/*/LC_MESSAGES/hg.mo
hgext/__index__.py

rust/target/
rust/*/target/

# Generated wheels
wheelhouse/

syntax: rootglob
# See Profiling in rust/README.rst
.cargo/config

syntax: regexp
^\.pc/
^\.(pydev)?project

# hackable windows distribution additions
^hg-python
^hg.py$