Remove app.lookup and make the functionality available as app.service

[daffl]

It turned out that app.lookup is somewhat redundant and not very descriptive. Instead I think it is a lot more explicit to make service lookup available as app.service(path):

app.service('todos').create({ text: 'Do something!' }, {}, function(error, data) {
  console.log('Created Todo', data);
});

To maintain backwards compatibility simply assign app.service as app.lookup like so:

app.configure(function() {
  this.lookup = this.service;
});

[daffl]

Also upgrades SocketIO to 1.1.0.