Permit spinner to function without nested routes (ie. at base route level)

[rpocklin]

Currently the design works for routes with a common parent. Ideally it should work even when the root state is empty. This may involve re-writing portions of the code or determining if this is the first time a view is loaded in the app (ie. initial bootstrapping of angular).

Ie. switching between /account and /settings should be able to show a spinner which is part of the initial ng-view.

Possibly relates to Issue #1