add non-functioning explosions

I'm tired and box2d ray casting is stupid so this'll have to do for today

server/game/room/world/body.js

@@ -22,13 +22,17 @@ class Body {
 
 	applyForce(x, y, center) {
 		let b = this.b2body;
-		b.ApplyForce(new b2Vec2(x, y), b.GetWorldCenter());
+		let c = center ? new b2Vec2(center.x, center.y) : b.GetWorldCenter();
+		b.ApplyForce(new b2Vec2(x, y), c);
 	}
 
 	applyTorque(f) {
 		this.b2body.ApplyTorque(f);
 	}
 
+	contact() {
+	}
+
 	tick() {
 		let pos = this.b2body.GetPosition();
 		let bounds = this.world.bounds;
@@ -74,6 +78,13 @@ class Body {
 			r: this.b2body.GetAngleRadians()
 		};
 	}
+
+	get vel() {
+		return {
+			xvel: this.b2body.GetLinearVelocity().x,
+			yvel: this.b2body.GetLinearVelocity().y
+		}
+	}
 }
 
 module.exports = Body;