Updated Pathfinding and UI updates

Added a countdown, Instruction for hiding leaderboard and game modes to
choose what board will appear
Merge branch 'master' of https://github.com/Polyphechris/PinballRacer

Conflicts:
	PinballRacer/PinballRacer/Game1.cs
	PinballRacer/PinballRacer/PinballRacer.csproj.Debug.cachefile
	PinballRacer/PinballRacerContent/Thumbs.db