add dirstate.lazyread, write atomically the dirstate
- add a dirstate.lazyread function that read only if it wasn't read before and
update all callers
- use the atomic keyword from util.opener to atomically write the dirstate
mercurial/dirstate.py
syntax: glob
*.elc
*.orig
*.rej
*~
*.so
*.pyc
*.swp
*.prof
tests/*.err
build
dist
doc/*.[0-9]
doc/*.[0-9].{x,ht}ml
MANIFEST
patches
mercurial/__version__.py
syntax: regexp
^\.pc/