German strings for commit 89b37d5f23722fa1162df17ec094f79626fd35ad

Not really sure about these two:

```xml
<string name="drawer_open">Drawer Open</string>
<string name="drawer_close">Drawer Close</string>
```

For one, there is no usual translation for the new Navigation Drawer that I am aware of, and a literal translation will not sound good. I have opted to translate the `Drawer` to `Navigation`, since it seems to be the most sane choice at the moment.

Another issue I have right now is, that I am not sure where you use these, and hence am missing context to decide whether you man the state "drawer is open", or the action "open the drawer". Can you eloborate? 
I went with the action now, so if you use it a the state, please do not merge yet and let me do another commit.

Thanks!