Create MegaBuster class to facilitate creation of BusterShots based on
stats. Add BusterPart interface to modify MegaBuster properties. Update
MegaPlayer to use a MegaBuster object. Update GeminiShot to conform to
new implementation.
Create GameCheat class to enable key-sequence cheat codes. Create
GameCheatListener to monitor keyboard events for cheats. Create
MegaCheat as specific cheat class for SeeteufelScreen. Create
BusterMaxCheat as an example cheat code. Attach GameCheatListener to the
Paused state in SeeteufelScreen.