changegroup3: introduce experimental.changegroup3 boolean config
In order to give us the freedom to change the changegroup3 format,
let's hide it behind an experimental config. Since it is required by
treemanifests, that will override the cg3 config.
#require test-repo
$ cd "$TESTDIR"/..
$ hg files 'set:(**.py)' | sed 's|\\|/|g' | xargs python contrib/check-py3-compat.py
contrib/casesmash.py not using absolute_import
contrib/check-code.py not using absolute_import
contrib/check-code.py requires print_function
contrib/check-config.py not using absolute_import
contrib/check-config.py requires print_function
contrib/debugcmdserver.py not using absolute_import
contrib/debugcmdserver.py requires print_function
contrib/debugshell.py not using absolute_import
contrib/fixpax.py not using absolute_import
contrib/fixpax.py requires print_function
contrib/hgclient.py not using absolute_import
contrib/hgclient.py requires print_function
contrib/hgfixes/fix_bytes.py not using absolute_import
contrib/hgfixes/fix_bytesmod.py not using absolute_import
contrib/hgfixes/fix_leftover_imports.py not using absolute_import
contrib/import-checker.py not using absolute_import
contrib/import-checker.py requires print_function
contrib/memory.py not using absolute_import
contrib/perf.py not using absolute_import
contrib/python-hook-examples.py not using absolute_import
contrib/revsetbenchmarks.py not using absolute_import
contrib/revsetbenchmarks.py requires print_function
contrib/showstack.py not using absolute_import
contrib/synthrepo.py not using absolute_import
contrib/win32/hgwebdir_wsgi.py not using absolute_import
doc/check-seclevel.py not using absolute_import
doc/gendoc.py not using absolute_import
doc/hgmanpage.py not using absolute_import
hgext/__init__.py not using absolute_import
hgext/acl.py not using absolute_import
hgext/blackbox.py not using absolute_import
hgext/bugzilla.py not using absolute_import
hgext/censor.py not using absolute_import
hgext/children.py not using absolute_import
hgext/churn.py not using absolute_import
hgext/clonebundles.py not using absolute_import
hgext/color.py not using absolute_import
hgext/convert/__init__.py not using absolute_import
hgext/convert/bzr.py not using absolute_import
hgext/convert/common.py not using absolute_import
hgext/convert/convcmd.py not using absolute_import
hgext/convert/cvs.py not using absolute_import
hgext/convert/cvsps.py not using absolute_import
hgext/convert/darcs.py not using absolute_import
hgext/convert/filemap.py not using absolute_import
hgext/convert/git.py not using absolute_import
hgext/convert/gnuarch.py not using absolute_import
hgext/convert/hg.py not using absolute_import
hgext/convert/monotone.py not using absolute_import
hgext/convert/p4.py not using absolute_import
hgext/convert/subversion.py not using absolute_import
hgext/convert/transport.py not using absolute_import
hgext/eol.py not using absolute_import
hgext/extdiff.py not using absolute_import
hgext/factotum.py not using absolute_import
hgext/fetch.py not using absolute_import
hgext/gpg.py not using absolute_import
hgext/graphlog.py not using absolute_import
hgext/hgcia.py not using absolute_import
hgext/hgk.py not using absolute_import
hgext/highlight/__init__.py not using absolute_import
hgext/highlight/highlight.py not using absolute_import
hgext/histedit.py not using absolute_import
hgext/keyword.py not using absolute_import
hgext/largefiles/__init__.py not using absolute_import
hgext/largefiles/basestore.py not using absolute_import
hgext/largefiles/lfcommands.py not using absolute_import
hgext/largefiles/lfutil.py not using absolute_import
hgext/largefiles/localstore.py not using absolute_import
hgext/largefiles/overrides.py not using absolute_import
hgext/largefiles/proto.py not using absolute_import
hgext/largefiles/remotestore.py not using absolute_import
hgext/largefiles/reposetup.py not using absolute_import
hgext/largefiles/uisetup.py not using absolute_import
hgext/largefiles/wirestore.py not using absolute_import
hgext/mq.py not using absolute_import
hgext/notify.py not using absolute_import
hgext/pager.py not using absolute_import
hgext/patchbomb.py not using absolute_import
hgext/purge.py not using absolute_import
hgext/rebase.py not using absolute_import
hgext/record.py not using absolute_import
hgext/relink.py not using absolute_import
hgext/schemes.py not using absolute_import
hgext/share.py not using absolute_import
hgext/shelve.py not using absolute_import
hgext/strip.py not using absolute_import
hgext/transplant.py not using absolute_import
hgext/win32mbcs.py not using absolute_import
hgext/win32text.py not using absolute_import
hgext/zeroconf/Zeroconf.py not using absolute_import
hgext/zeroconf/Zeroconf.py requires print_function
hgext/zeroconf/__init__.py not using absolute_import
i18n/check-translation.py not using absolute_import
i18n/polib.py not using absolute_import
mercurial/cmdutil.py not using absolute_import
mercurial/commands.py not using absolute_import
setup.py not using absolute_import
tests/filterpyflakes.py requires print_function
tests/generate-working-copy-states.py requires print_function
tests/get-with-headers.py requires print_function
tests/heredoctest.py requires print_function
tests/hypothesishelpers.py not using absolute_import
tests/hypothesishelpers.py requires print_function
tests/killdaemons.py not using absolute_import
tests/md5sum.py not using absolute_import
tests/mockblackbox.py not using absolute_import
tests/printenv.py not using absolute_import
tests/readlink.py not using absolute_import
tests/readlink.py requires print_function
tests/revlog-formatv0.py not using absolute_import
tests/run-tests.py not using absolute_import
tests/seq.py not using absolute_import
tests/seq.py requires print_function
tests/silenttestrunner.py not using absolute_import
tests/silenttestrunner.py requires print_function
tests/sitecustomize.py not using absolute_import
tests/svn-safe-append.py not using absolute_import
tests/svnxml.py not using absolute_import
tests/test-ancestor.py requires print_function
tests/test-atomictempfile.py not using absolute_import
tests/test-batching.py not using absolute_import
tests/test-batching.py requires print_function
tests/test-bdiff.py not using absolute_import
tests/test-bdiff.py requires print_function
tests/test-context.py not using absolute_import
tests/test-context.py requires print_function
tests/test-demandimport.py not using absolute_import
tests/test-demandimport.py requires print_function
tests/test-dispatch.py not using absolute_import
tests/test-dispatch.py requires print_function
tests/test-doctest.py not using absolute_import
tests/test-duplicateoptions.py not using absolute_import
tests/test-duplicateoptions.py requires print_function
tests/test-filecache.py not using absolute_import
tests/test-filecache.py requires print_function
tests/test-filelog.py not using absolute_import
tests/test-filelog.py requires print_function
tests/test-hg-parseurl.py not using absolute_import
tests/test-hg-parseurl.py requires print_function
tests/test-hgweb-auth.py not using absolute_import
tests/test-hgweb-auth.py requires print_function
tests/test-hgwebdir-paths.py not using absolute_import
tests/test-hybridencode.py not using absolute_import
tests/test-hybridencode.py requires print_function
tests/test-lrucachedict.py not using absolute_import
tests/test-lrucachedict.py requires print_function
tests/test-manifest.py not using absolute_import
tests/test-minirst.py not using absolute_import
tests/test-minirst.py requires print_function
tests/test-parseindex2.py not using absolute_import
tests/test-parseindex2.py requires print_function
tests/test-pathencode.py not using absolute_import
tests/test-pathencode.py requires print_function
tests/test-propertycache.py not using absolute_import
tests/test-propertycache.py requires print_function
tests/test-revlog-ancestry.py not using absolute_import
tests/test-revlog-ancestry.py requires print_function
tests/test-run-tests.py not using absolute_import
tests/test-simplemerge.py not using absolute_import
tests/test-status-inprocess.py not using absolute_import
tests/test-status-inprocess.py requires print_function
tests/test-symlink-os-yes-fs-no.py not using absolute_import
tests/test-trusted.py not using absolute_import
tests/test-trusted.py requires print_function
tests/test-ui-color.py not using absolute_import
tests/test-ui-color.py requires print_function
tests/test-ui-config.py not using absolute_import
tests/test-ui-config.py requires print_function
tests/test-ui-verbosity.py not using absolute_import
tests/test-ui-verbosity.py requires print_function
tests/test-url.py not using absolute_import
tests/test-url.py requires print_function
tests/test-walkrepo.py requires print_function
tests/test-wireproto.py requires print_function
tests/tinyproxy.py requires print_function