Major refactor of connection code

 Connection code from HostActivity and FanActivity pulled into ConnectionService and MessagingService.

All connection management code now lives in ConnectionService.  This includes
bluetooth discovery, host/fan connection management, and sending and receiving
messages.

All messaging management code now lives in MessagingServices.  It receives new
IMessage objects from the ConnectionService, decomposes the messages into their
parts, and sends a broadcast intent/action to the rest of the system to
represent each message.  This decouples the message and network layer from the
rest of the app.

HostActivity and FanActivity have been modified to use these services.

Currently broken: remote fan discovery.  Not too far from being complete...