Bug 860841.  Hook up the proto chain of a WebIDL interface object to the interface object of its nearest ancestor interface that has one, as if these were ES6 classes.  r=peterv
Bug 742206 part 1.  Introduce a simple mozilla::dom::Date for use in WebIDL bindings.  r=smaug
Bug 742206 part 2.  Implement WebIDL parser support for Date.  r=smaug,khuey
Bug 742206 part 3.  Implement type conversions for Date in WebIDL.  r=smaug
Bug 742206 part 4.  Start using the new Date stuff for HTMLInputElement.valueAsDate.  r=smaug
Add test for bug 560072.