Add ranged combat animations

[Mikolaj]

Draw the flight of the projectile in ranged combat. Use the digital line algorithm, draw in real time. We need some kind of timing and it should be independent of the computer speed and drawing frontend.

[Mikolaj]

This is now simplified by projectiles being actors. To visualize movement of projectiles that is faster than the player, we need to set a frame rate, e.g., 5 frames per second and show the extra frames as an animation. See AllureOfTheStars/Allure#4 for an old discussion.