Specific paths override more general paths

For example, if your filter file includes paths like:

```
a/b
a/b/c/d
```

Then, if it exists, path `a/b/e` winds up getting ignored.  It seems like a better behavior would be for it to issue a warning that path `a/b/c/d` is overridden by the more general path `a/b` which would include path `a/b/e`