Upgrade `twitter` and `googleapis` packages.

Change-Id: Iefaaf01defe00e9bbf194852bd80956d21b58c6b
Upgrade to Meteor 0.9.4 (mobile and testing).

Meteor release notes:
https://www.meteor.com/blog/2014/10/13/meteor-094-mobile-and-testing
https://github.com/meteor/meteor/blob/release/METEOR@0.9.4/History.md

Change-Id: I917788be4983bf9314f77576e68f79d9fd92538c
Rename UI.registerHelper -> Template.registerHelper

Change-Id: Icdd3dc0bc7f9ff0a2dde32c066536bf070d38bb4
Use Template#helpers method to define helpers.

Previously, helpers were added directly as properties of the template
object.  That has been deprecated now (in Meteor >= 0.9.4) in favor of
passing a hash to `Template#helpers`.

Change-Id: I176e8270ed615cd5692a34d0d42dc216114e8cac
Upgrade to Meteor 1.0.

Meteor release notes:
https://www.meteor.com/blog/2014/10/28/meteor-1-0
https://github.com/meteor/meteor/blob/release/METEOR@1.0/History.md

Change-Id: Iae7059a082fb1d8773bc19d525c229833ba2aae6
Add some items to the TODO list.

Change-Id: I2b326c08aae849be68e2dacb65fc14fa9c1e0429