Use icons in the top navigation menu

Hi Daniel,

The first pull small request :)

For better usage of space in the top navigation menu, the search and reload button texts have been replaced with icons. Also the label "Select log" has been removed.

Before:
![image](https://f.cloud.github.com/assets/359614/2384025/9349e72e-a906-11e3-99e2-8ecd493bab5c.png)

After:
![image](https://f.cloud.github.com/assets/359614/2384020/84f4ef48-a906-11e3-9e0f-f2073326de56.png)


/ Regin