Data Table letter case doesn't match other vis types

The "Data Table" vis type doesn't have the same casing as the other vis types (first word capitalized, following words uncapitalized).

![screen shot 2014-11-10 at 10 35 47 am](https://cloud.githubusercontent.com/assets/1178348/4980428/099f7588-6900-11e4-9968-b6676f3a2cf8.png)