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...
Added Play/Pause/Skip messages and unbind call in onDestroy
Added comment to the top of ServiceLocator, talking about pitfalls when using
services.

Changed Runnable to a more specific interface, for on bind listeners.
Fixed StringMessage sending to support both fans and hosts
Merge pull request #36 from theJenix/messaging_service

Major refactor of connection code