perf(scope): optim createChild() which always append at the end
perf(scope): optim createChild() which always append at the end

Closes #626
rkirov/angular.dart,winstonewert/angular.dart,SibuStephen/angular.dart,winstonewert/angular.dart,giovannicandido/angular.dart,rkirov/angular.dart,ronlobo/angular.dart,rkirov/angular.dart,giovannicandido/angular.dart,hitesh97/angular.dart,trinarytree/angular.dart,hitesh97/angular.dart,trinarytree/angular.dart,ronlobo/angular.dart,hitesh97/angular.dart,giovannicandido/angular.dart,SibuStephen/angular.dart,trinarytree/angular.dart,winstonewert/angular.dart,winstonewert/angular.dart,ronlobo/angular.dart,rkirov/angular.dart,SibuStephen/angular.dart,SibuStephen/angular.dart,ronlobo/angular.dart,trinarytree/angular.dart,hitesh97/angular.dart