Merge pull request #2817 from Ms2ger/xhr-response-json

Handle exceptions from JS_ParseJSON in XMLHttpRequest.response.
Remove empty objects from Bindings.conf.

This also comments out an unused mixin interface, and adds
NoInterfaceObject to one that missed it.
Pass a JSContext and a reflector to RegisterBindings::Register.

This makes the generated code less dependent on the fact that all global
objects are Windows.
Move the call to RegisterBindings::Register into WindowBinding::Wrap.
Update the rust-mozjs submodule pointer.
Fix DOMImplementation should be linked to the Document

This fixes issues 2230.
Merge pull request #2816 from Ms2ger/bindings.conf

Cleanup Bindings.conf.
Move to an .ini file to define the parts of wpt we run.

This is more maintainable as we add more tests.
Merge pull request #2822 from Ms2ger/wpt-ini

Move to an .ini file to define the parts of wpt we run; r=Manishearth
Merge pull request #2771 from jviereck/fix_2230_link_DOMImplementation_to_document

Link DOMImplementation to the Document; r=Ms2ger
Merge pull request #2820 from Ms2ger/RegisterBindings

Move the call to RegisterBindings::Register into WindowBinding::Wrap; r=jdm
Merge pull request #2821 from Ms2ger/update-rust-mozjs

Update the rust-mozjs submodule pointer; r=jdm
Make Element.remove_attribute take &str instead of DOMString
Update web-platform-tests expectations.
Merge pull request #2824 from jgraham/remove_attribute_str

Make Element.remove_attribute take &str instead of DOMString; r=Ms2ger
Add stringcache to build, now that phf is working on android
Remove the unused window field from ValidityState.

It is only necessary if the ValidityState would create new objects, which it
doesn't.
Remove the unused 'obj' local from the construct hook.
Simplify the initialization of Performance.
Remove the unused window field from NodeList.