Instead of crashing if userInfo is not yet available.
statusMessage is removed for now from UserUpdated events,
and the users model items will have a "loading" property.
http://es6-features.org/#PropertyShorthand
Instead of doing {"foo": foo, "bar": bar, ...}, we can just do
{foo, bar} now.
The function parameters of EventHandlers have all been renamed to
camelCase to make use of this, as the JS style conventions intend.
Other functions will follow in a later commit.
