add commands, mongo_proxy and queryset
adding queryset.dart, mongo_proxy.dart, and commands.dart as a part of model.dart
make attr on CreateCommand private
fix attr on CreateCommand
Upgrade for breaking changes of 'dart:mirrors'
fix typo, error should be called with toString(), because error is an instance
made handleData() an abstract method
create actual usable fields, for basic validation (untested)
adapting to change on mirrors API, where every class member should be accessed from declarations getter
create model API
close server only when response is closed
add model test