Trust extenders are not issuers and should not be labeled as such

Before:
![screen shot 2014-12-04 at 1 35 29 pm](https://cloud.githubusercontent.com/assets/5728307/5306621/b0692234-7bba-11e4-9056-43a53f8fb8f7.png)

After:
![screen shot 2014-12-04 at 1 38 53 pm](https://cloud.githubusercontent.com/assets/5728307/5306648/e8cef66c-7bba-11e4-8b85-d7c1556706c3.png)

https://www.stellar.org/viewer/#test/gBAde4mkDijZatAdNhBzCsuC7GP4MzhA3B