Listener does not follow symlinks

Consider the following structure:

```
main
|- sub1
|  |- file1
|- sub2 --> somewhere
   |- file2
```

where `sub2` is a symlink to some other (read- and writable) directory. Assume we watch `main` and ignore nothing.

While changes to `file1` are dutifully reported, changes to `file2` are not.
