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
#!/bin/shhg init acd aecho a > foohg add foohg commit -m 1 -d "0 0"rm foohg remove foohg commit -m 2 -d "0 0"cd ..hg clone a b