message: remove mixin by name
diff: @@ -111,7 +111,7 @@ function emitDom() {
  if (obj["callback-interfaces"]) result["callback-interfaces"]!.interface = filterInterface(obj["callback-interfaces"]!.interface, template["callback-interfaces"] && template["callback-interfaces"]!.interface);
  if (obj.dictionaries) result.dictionaries!.dictionary = filterDictionary(obj.dictionaries.dictionary, template.dictionaries && template.dictionaries.dictionary);
  if (obj.enums) result.enums!.enum = filterEnum(obj.enums.enum, template.enums && template.enums.enum);
  - if (obj.mixins) result.mixins!.mixin = filterInterface(obj.mixins.mixin, template.mixins && template.mixins.mixin);
  + if (obj.mixins) result.mixins!.mixin = filterProperties(obj.mixins.mixin, mixin => !(template.mixins && template.mixins!.mixin[mixin.name]));
  if (obj.interfaces) result.interfaces!.interface = filterInterface(obj.interfaces.interface, template.interfaces && template.interfaces.interface);
  if (obj.typedefs) result.typedefs!.typedef = obj.typedefs.typedef.filter(t => !(template.typedefs && template.typedefs.typedef.find(o => o["new-type"] === t["new-type"])));
  