feat(autoid): Added auto assignment of ids to new items created with Firebase.
feat(modelWriter): Implemented positional updating in updatedFromProtocol.
feat(modelWriter): Handled more cases with updatedFromProtocol.
fix(pipeline): Fix pipeline for adding an element to a collection.
feat(integration): Added basic integration test.
feat(binder.key): Added support for binder.key in differ and binder.
Added more info to the README, to explain the APIs at their current status.
readme: Added real content to readme.