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

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/