implement HTMLDataListElement.options
Remove a dead argument from CGAbstractMethod methods.
Return a JS<T> from *Binding::Wrap rather than a JSObject.

This lets us avoid the sketchy tricks in JS::new and Window::new, where we
kept an unsafe pointer to the native object across the Wrap call that
consumed the owned pointer.
Implement HTMLFieldSetElement.elements.(fixes #1843)
Clean files associated with static linking
auto merge of #1865 : lpy/servo/issue1843, r=jdm

see #1843
auto merge of #1855 : lpy/servo/issue1842, r=jdm

see #1842
When I tried to use like `datalist.options[0].value`, it returned nothing. So is it implemented?
auto merge of #1910 : Ms2ger/servo/dead-arg-CGAbstractMethod, r=jdm
auto merge of #1915 : Ms2ger/servo/wrap-return-js, r=jdm

This lets us avoid the sketchy tricks in JS::new and Window::new, where we
kept an unsafe pointer to the native object across the Wrap call that
consumed the owned pointer.
auto merge of #1941 : larsbergstrom/servo/clean_rlib, r=metajack

Three things changed with the `make clean` process:
- Remove the *.rlib files associated with the Servo crates
- Remove the libservo-*.a file, which we will (Very Soon Now) generate now on Android instead of a .so
- Update all the submodules, which have corresponding *.rlib file cleanup changes