Install ui-bg_glass_75_e6e6e6_1x400.png

Using ipython-2.0.0-rc1.win-amd64-py3.4 I the following warning:
```
WARNING:tornado.access:404 GET /static/components/jquery-ui/themes/smoothness/images/ui-bg_glass_75_e6e6e6_1x400.png (127.0.0.1) 0.00ms referer=http://127.0.0.1:8888/notebooks/Rmagick.ipynb
```