Consistent formatting for login/signup elements

Before:
![before](http://puu.sh/azSeN/d1be3f124a.png)

After:
![after](http://puu.sh/azSe4/4ffb356082.png)

Also excludes the logged in element from the background hover effect:

![hover](http://puu.sh/azSYq/25fd6c33c3.png)