jashkenas/backbone — pull request #2936 by gsmlg (2013-12-24 13:55:47+00:00)
Title: support model.set('user.name', 'Joe')

model.set('user', {name: 'George', email: 'george@example.com'})
model.set('user.name', 'Joe');
model.get('user') // => {name:'Joe', email: 'george@example.com'}
model.set('user.email', 'Joe@abc.net')
model.get('user') // => {name:'Joe', email: 'Joe@abc.net'}
model.get('user.name') //=> 'Joe'

support access an object attribute with "."