remove: work directly off status
This allows us to use a single directory walk and to trivially ignore
unknown files. The resulting code is also easier to follow.
#!/bin/sh
hg init a
hg clone a b
cd a
echo '[paths]' >> .hg/hgrc
echo 'dupe = ../b' >> .hg/hgrc
hg in dupe | fgrep '../'
cd ..
hg -R a in dupe | fgrep '../'
true