coal/paper: Wrap diff in <pre/>
In text-mode browsers the diff is otherwise rendered
as just one long line per file. Other styles do the same.
#!/bin/sh
hg init dir
cd dir
echo bleh > bar
hg add bar
hg ci -m 'add bar'
hg cp bar foo
echo >> bar
hg ci -m 'cp bar foo; change bar'
hg debugrename foo
hg debugindex .hg/store/data/bar.i