Allow callers to pass in the dirstate lock in most localrepo.py funcs. This makes it possible to take the lock once and commit a large number of patches, without having to read and write the dirstate for each patch.

#!/bin/sh

hg init a
cd a
echo a > foo
hg add foo
hg commit -m 1 -d "0 0"
rm foo
hg remove foo
hg commit -m 2 -d "0 0"
hg export 0
hg export 1
hg log -p -r 0
hg log -p -r 1

cd ..
hg clone a b