Added sprites for the rocket flames "LoFlameSpr.png" and the sprites for the explosion rough "ExplosionSpr.png."

Flames are 2 frames long, with each frame at 24 x 29 (W x H).
Explosion is 10 frames long, with each frame at 100 x 100 (W x H).

I'm going to improve the explosion quality later, this serves as a weird looking placeholder.