Merge branch 'improve-navigation' into 'master'

Improve GitLab UI

* move logout button to top right

![Screenshot_2015-06-08_16.56.13](https://gitlab.com/gitlab-org/gitlab-ce/uploads/7de04fab52ad6b742dbea100674f9671/Screenshot_2015-06-08_16.56.13.png)

* remove issue/mr title truncation on index pages. For smaller screens it allow to read complete title of issue

![Screenshot_2015-06-08_16.57.55](https://gitlab.com/gitlab-org/gitlab-ce/uploads/9dcaadfba14f8561c12fcd29a2e70112/Screenshot_2015-06-08_16.57.55.png)

* Improve mobile UI for several pages

See merge request !783