Makefile: Added SDL_image for sprite loading.
eagle.cpp: getMainEngineStatus: return mainthrust.
ship.hpp: Added three different flame sprites.
ship.cpp: Added the three flame sprites.
moonlanding.hpp: Added stars background and ground functions
moonlanding.cpp: Added stars background and ground functions
main.cpp: Added stars background and ground.
flame_big.png: Big flame sprite.
flame_mid.png: Middle flame sprite.
flame_low.png: Small flame sprite
ship.png: Ship sprite