Existing lines are not emitted until the file is updated

The existing lines are emitted only when the file changes. This is not like tail(1) which dumps directly the current content.

Is there a way to achieve this or is there a missing flag?

Currently, I worked around with:

```
FileObservable.tailer()
.file(file)
.tailText()
.startWith(Observable.defer(() -> {
try {
return Observable.from(Files.readAllLines(Paths.get(file)));
} catch (IOException e) {
return Observable.error(e);
}
})
```

(Note: I defer in order to be sure that I do not miss lines)