Autofocus on email field in login

With this addition email field will be in focus by default like on the screenshot:

![screen shot 2014-03-06 at 16 36 09](https://f.cloud.github.com/assets/522155/2344944/f0775208-a52b-11e3-996f-a80ef701cccf.png)

For the better usability :grinning: