revlog: rewrite several method docstrings - methods: findmissing(), nodesbetween(), descendants(), ancestors() - the goal is precise, concise, accurate, grammatical, understandable, consistently formatted docstrings

#!/bin/sh

mkdir a
cd a
hg init
echo foo > b
hg add b
hg ci -m "b" -d "1000000 0"

chmod -w .hg/store

cd ..

hg clone a b

chmod +w a/.hg/store # let test clean up

cd b
hg verify