diffstat: scale adds/removes proportionally to graph width
The previous method of scaling had a tendency to include graph lines that
went past the output width when the file with the most changes had a very
large number of changes.
#!/bin/sh
hg init a
cd a
mkdir a
echo a > a/b
hg ci -Am m
hg rm a
hg ci -m m a
mkdir a b
echo a > a/b
hg ci -Am m
hg rm a
cd b
# relative delete
hg ci -m m ../a