Adding parsing for a `@response_class` Tag

This commit adds support for the (swagger 1.0 style) definition of the `responseClass` of an operation.

Example:
![image](https://cloud.githubusercontent.com/assets/569413/3755430/1db7eba8-1825-11e4-9e0f-f607efbca9fa.png)

What does this name `OwnershipList` correspond to?