docs: change `troubles` references to `instability`
Per https://www.mercurial-scm.org/wiki/CEDVocabulary. There are a couple
instances of 'troublesome' which probably need a word, as deriviatives of
'instability' didn't really fit. At least some of these are in the unlinked
obs-terms.rst page.
# setup config and various utility to test new heads checks on push
. $TESTDIR/testlib/common.sh
cat >> $HGRCPATH <<EOF
[ui]
# simpler log output
logtemplate ="{node|short} ({phase}): {desc}\n"
[phases]
# non publishing server
publish=False
[extensions]
# we need to strip some changeset for some test cases
strip=
evolve=
EOF
setuprepos() {
echo creating basic server and client repo
hg init server
cd server
mkcommit root
hg phase --public .
mkcommit A0
cd ..
hg clone server client
}