Issue 181 wear support

@barbeau This is getting quite large so I figure I'll take a break and get some feedback.

I would like to get an app on the wearable which has 2 use cases:
1.  Browses starred stops.
2.  View ArrivalInfo for a stop.

Designwise, I created a long running ```NodeService``` on the device which is the sole interface for the wearable to the Oba data.

The wearable fires messages to the ```NodeService``` to request data synchronization updates.

The NodeService will then update the Wearable datastores with the requested data updates via Wearable.DataApi calls.  The source of these data updates can be direct calls to the ObaApi or data from the ObaProvider, depending on the use case requirements.

For now I've only implemented the first use case of retrieving Starred Stops.

Implementing a polling ArrivalInfo hook into the NodeService would be next on my agenda.

I tried to document any areas I feel required extra inspection with todo tags.
Moving forward I will remove the play services dependency from the core module and put the appropriate dependencies into the wear and oba modules.