Merge pull request #2678 from Ms2ger/CreateInterfaceObjects2-protoClass

Stop pretending that CreateInterfaceObjects2 can return the interface object.
Use internal mutability for XMLHttpRequest.
Merge pull request #2663 from saneyuki/trace_comment

Mention the usecase of Traceable/Untraceable.
Merge pull request #2670 from fdipilla/ticket#2150

Added path space support (Fixes #2150)
Merge pull request #2669 from Manishearth/wpt_up

Update to latest wpt
Merge pull request #2664 from Manishearth/untraceable

Use Traceable for primitive types, DOMString, and NodeFlags
Merge pull request #2658 from saneyuki/xhr

Use internal mutability for XMLHttpRequest.
Enable IRC notifications from Travis CI
Correct the condition for generating CGGetConstructorObjectMethod.

As we don't actually implement the feature for which this is needed, I've
commented the call out for now and mentioned the issue for the feature.
Merge pull request #2679 from larsbergstrom/IRC_notifications

Enable IRC notifications from Travis CI
Generate code for NoInterfaceObject interfaces in InterfaceTypes and InheritTypes.

There is no reason for those interfaces to be excluded.
Pass the interface object-related arguments to CreateInterfaceObjects2 together in an Option.

This clarifies the code and fixes our support of NoInterfaceObject interfaces.
Use iterators to make some logic clearer
Use Option functions to make logic clearer
Make move mutation out of compute_minimum_ascent_and_descent
Remove some unnecessary mutable references
Keep calling the DefineDOMInterface method for NoInterfaceObject interfaces.

DefineDOMInterface also creates the proxy handler for proxy classes, so it
should be called in this case as well.
Make AttrList NoInterfaceObject (fixes #1223).
Use Option::expect instead of pattern matching in try_append_to_line_by_new_line
Clean up skip_while iteration