Ensure short commercial titles appear centered below g marque

Before:

![screen shot 2014-11-26 at 11 49 07](https://cloud.githubusercontent.com/assets/813383/5200833/17ecc910-7562-11e4-9e9b-f11f2b50012d.png)

After:

![screen shot 2014-11-26 at 11 45 57](https://cloud.githubusercontent.com/assets/813383/5200835/1d268524-7562-11e4-82b7-0e3b78f129bf.png)
![screen shot 2014-11-26 at 11 46 24](https://cloud.githubusercontent.com/assets/813383/5200838/1d5321b0-7562-11e4-94b4-12b96dfbc5f7.png)
![screen shot 2014-11-26 at 11 47 06](https://cloud.githubusercontent.com/assets/813383/5200836/1d4fd53c-7562-11e4-8fe5-99734408499f.png)

…while behaving normally if the text is longer:
![screen shot 2014-11-26 at 11 47 39](https://cloud.githubusercontent.com/assets/813383/5200837/1d5128f6-7562-11e4-9259-9ee87603f45a.png)