Move commands.forget over to using new walk code.
With no names, it now recursively forgets everything, as is the default
behaviour of other commands. And prints the names of all files it
hasn't specifically been told to forget.
#!/bin/sh -x
hg --debug init
echo this is a1 > a
hg add a
hg commit -m0 -d "0 0"
echo this is b1 > b
hg add b
hg commit -m1 -d "0 0"
hg manifest 1
echo this is c1 > c
hg rawcommit -p 1 -d "0 0" -m2 c
hg manifest 2
hg parents
rm b
hg rawcommit -p 2 -d "0 0" -m3 b
hg manifest 3
hg parents
echo this is a22 > a
hg rawcommit -p 3 -d "0 0" -m4 a
hg manifest 4
hg parents
echo this is c22 > c
hg rawcommit -p 1 -d "0 0" -m5 c
hg manifest 5
hg parents
# merge, but no files changed
hg rawcommit -p 4 -p 5 -d "0 0" -m6
hg manifest 6
hg parents
# no changes what-so-ever
hg rawcommit -p 6 -d "0 0" -m7
hg manifest 7
hg parents