Update examples to 0.12 and use object-assign

0.12 deprecates usage of merge and copyProperties and autofactories

Object.assign is provided in react/lib/Object.assign as of now, but may
move to a more freely accessible place in the future. Towards this
expectation, object-assign will be used in preparation.
Merge branch 'update-examples' of git://github.com/kimagure/flux into kimagure-update-examples

Conflicts:
	docs/TodoList.md
	examples/flux-chat/js/dispatcher/ChatAppDispatcher.js
	examples/flux-chat/js/stores/MessageStore.js
	examples/flux-chat/js/stores/ThreadStore.js
	examples/flux-chat/js/stores/UnreadThreadStore.js
	examples/flux-chat/js/stores/__tests__/UnreadThreadStore-test.js
	examples/flux-chat/package.json
	examples/flux-todomvc/js/dispatcher/AppDispatcher.js
	examples/flux-todomvc/js/stores/TodoStore.js
	examples/flux-todomvc/js/stores/__tests__/TodoStore-test.js
	examples/flux-todomvc/package.json
Merge branch 'kimagure-update-examples'