Workaround for thrift issue makes paramBreak a required field; tests updated

This fixes an issue where FormaValues were not being properly serialized into our pail. Specifically, the `paramBreak` field was getting reset to 0.0. [This gist](https://gist.github.com/robinkraft/5424034) demonstrates the problem. Could this be an issue with [Pail](https://github.com/nathanmarz/dfs-datastores) not correctly serializing optional fields inside nested objects? Packing and unpacking the thrift objects (without passing through a pail) works fine with optional fields.

Our workaround is to make the `paramBreak` field required. All tests pass.