add missing comma(s) in api examples

Added some missing commas in the api examples.

**before / after:**
![bildschirmfoto von 2013-08-30 21 11 29](https://f.cloud.github.com/assets/327488/1060073/2e8f0b0c-11a8-11e3-9a9d-1a834278b177.png) / ![bildschirmfoto von 2013-08-30 21 11 35](https://f.cloud.github.com/assets/327488/1060075/3105c24a-11a8-11e3-8aeb-de640b1d0260.png)