Bug 865076, follow the XPCOM rules when using parent pointer, r=mccr8

--HG--
extra : rebase_source : c4d45f53bb15df09495714cb0955e3d2d9c684b6
Bug 799816.  Try to not have preload sheets (or other unreferenced sheets) hanging out in our mCompleteSheets hashtable.  r=dbaron
Bug 864535.  Drop some comments from WebIDL proxy [[Delete]] implementations, since the spec has changed.  r=waldo
Bug 843264.  Allow returning sequences of non-primitive types from callback methods.  r=mccr8
Bug 862629 part 1.  Stop playing compartment games with WebIDL callbacks and just use the given object as-is.  r=peterv
Bug 862629 part 2.  Remove the now-unused scope object bit in js-to-native conversions.  r=peterv
Bug 864590.  Assert that the object is not null when wrapping WebIDL objects.  r=peterv