Reimplement Response#{value, value=} using response class.  #3410.
Eager-load a response's questions and answers by default.  #3410.

Response#value and Response#value= will always load the answer, but on a
philosophical point, I don't think a Response makes sense unless you
have its answer and question contexts.  Might as well just load them up
front.
Lock to a version of Surveyor without Response default order.  #2744.

This is a temporary fix for queries that were failing with ambiguous
column references.

More information:

* https://github.com/NUBIC/surveyor/issues/423
* http://git.io/jRSj5A