Split the user ssh keys by newline, not the characters "\n"

**before:**
```
GET /user.keys

ssh-rsa ...\nssh-rsa ...\nssh-rsa ...
```
Sourcecode:
![bildschirmfoto von 2014-02-11 19 02 27](https://f.cloud.github.com/assets/327488/2140275/0f7f9406-934a-11e3-856a-cadd50daeb62.png)
Browser-View:
![bildschirmfoto von 2014-02-11 19 04 25](https://f.cloud.github.com/assets/327488/2140296/607bddb0-934a-11e3-8abe-3c042de35245.png)


**after:**
```
GET /user.keys

ssh-rsa ...
ssh-rsa ...
sha-rsa ...
```
Sourcecode:
![bildschirmfoto von 2014-02-11 19 01 36](https://f.cloud.github.com/assets/327488/2140274/0f6a5e9c-934a-11e3-8529-47db34c9f178.png)