Made the player's orbit more realistic

- AngleRelativeToOrb gets incremented based on how far the Player is
from the Orb (more realistic), so the Player now slows down when
orbiting at a farther radius
- Changed orbitalDistance to orbitalRadius
- Changed radiansPerSecond to pixelsPerSecond
- Added a variable to hold the orbitTransitionRate
- Refactored update: into smaller methods
Merge branch 'feature-player_moves_at_same_speed' into development