evolve: store --update flag state in evolvestate file
Part of 9c522bdfc846 that wasn't yet accepted.
. $TESTDIR/testlib/pythonpath.sh
mkcommit() {
echo "$1" > "$1"
hg add "$1"
hg ci -m "$1"
}
getid() {
hg log --hidden --template '{node}\n' --rev "$1"
}
cat >> $HGRCPATH <<EOF
[alias]
debugobsolete=debugobsolete -d '0 0'
EOF