All Room names now appear when any room is selected.
Only show story text on first visit in AudioRoom example
Tidy up Start() function comment
Updated Room template to give better examples
Miscellaneous refactors to hide complexity

- Added GameController facade class to hide complexity and provide a
single place to access all Fungus functionality
- Removed existing facade methods on Game (redundant)
- Removed Room.OnLeave (not necessary, and possibly dangerous)
- Renamed AnimationListener.OnAnimationEvent() to CallRoomMethod (more
descriptive).
- Button component will now use existing Collider2D if one exists.
- Game component now manages CameraController configuration
- Game now adds CameraController and CommandQueue at runtime instead of
in editor (less user configuration)
- CommandQueue now owns the methods for executing command methods
- Added StringTable class to manage key/string lookups
- Moved SubstituteStrings() and FormatLinkText() to new StringTable
class
- Room.Enter() method is now private to hide implementation details
- Updated example project to match changes