Add sprite for spaceship propulsion

[boracayalex]

Add a "fire/ignition" like sprite on the back of the spaceship that appears when thrusting.

[boracayalex]

Is added but rotation doesnt match the spaceship sprite

[boracayalex]

it works properly now! instead of adding an isolated propulsionsprite in extension of the spaceshipsprite, the spaceship sprite is just replaced with another spaceship sprite that has propulsion in it