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
mkdir t
cd t
hg init
echo a > a
hg add a
hg commit -m "test" -d "0 0"
hg verify
hg parents
hg status
hg undo
hg verify
hg parents
hg status