Change active service before changing players
Fix bug where shutdown indicator didn't change to amber before flashing

Uses the new queue functionality in radiodan-client to queue up
transitions to ensure the power LED changes to amber first and then
begins flashing.
Flash power light when volume message has been received
Load BBC services using playlist URL rather than direct audio streams

Each service now returns a type. 'playlist' types are sent to the
player using .load() and other types use .add().
Replace ractive tap plugin with ractive touch
Trigger custom shutdown event after holding for 3 secs
Shutdown using web UI
Add label to explain feature
Fix masthead layout