fix the cat command
- improve localrepo.walk when passed a node
- make the differents walk commands in commands.py accept a node
- change commands.cat to walk over a revision
- add a test
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 1 changesets, 1 total revisions
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
verify failed
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 1 changesets, 1 total revisions
commit failed