Cleared out the gameplay scene in preparation for features

Removed debugging code
Added a player

Player class added
Player sprite gets drawn in GameplayLayer
Deleted GameplayScene (unneeded)
Added orb and player orbits orb

The Player orbits the Orb at 0.1 degrees per update
Player's rotation changes as it orbits

The Player's rotation is now correctly set
Changed the intro layer to the GameplayLayer for debugging purposes
Added a radians per frame variable to Player (25)
Merge branch 'feature-player_revolving_around_orb' into development