Bug 948096.  Warn when people use window._content.  r=smaug,myk
Bug 949264 part 1.  Share more codegen between events and CGNativeMember.  r=smaug
Bug 949264 part 2.  Support union members in generated events.  r=smaug
Bug 949264 part 3.  Use aRetVal for the outparam return value for CGNativeMember.  r=smaug
Bug 949271.  Fix callback and JS-implemented codegen for sequence-of-union and variadic-union arguments.  r=smaug
Bug 949471.  history.state should be null, not undefined, when there is no state.  r=smaug
Bug 942164 - Refcount imgRequest consumers. r=seth