Added Drones!

Today I worked on drones. What are drones? Drones are additional ships that follow the player and shoot with him / her. There's currently a hard (at least, harder than usual) limit of two drones; I tried it without a limit and had a massive wall of lead emitting from the player in short order. Still, technically, not invulnerable—you can't shoot down other bullets, after all—but pretty freakin' close. Two drones are still a massive amount of lead, but are more confined.

I'll consider turning up the maximum drone count in the future, once the enemies are smarter or more hardened. This does make me feel more comfortable with the strength of the player ship, though. It's much more involving when you've got a massive amount of ammo to throw at your opponent, but can only handle a single bullet before resetting minus a life.

I had to set up a waypoint chain trailing behind the player, updating periodically, to get these to work; there may be other uses for that chain of waypoints in the future. I was inspired by how some of the AI in Half-Life worked; it's surprisingly portable to horizontal shootemups like Shoo Dem Up!

Everybody have fun!