Thrown Item Physics (#120)

* Thrown object speed is now based on force.
Fixed BoundingBox namespace.

* 100% more throwing.
CollisionGroup enum.

* Update Engine.

Content.Server/GameObjects/Components/Projectiles/ThrownItemComponent.cs

@@ -0,0 +1,36 @@
+using System.Collections.Generic;
+using Content.Server.GameObjects.Components.Projectiles;
+using Content.Shared.Physics;
+using SS14.Shared.Interfaces.GameObjects;
+using SS14.Shared.Interfaces.GameObjects.Components;
+
+namespace Content.Server.GameObjects.Components
+{
+    class ThrownItemComponent : ProjectileComponent, ICollideBehavior
+    {
+        public override string Name => "ThrownItem";
+
+        void ICollideBehavior.CollideWith(List<IEntity> collidedwith)
+        {
+            foreach (var entity in collidedwith)
+            {
+                if (entity.TryGetComponent(out DamageableComponent damage))
+                {
+                    damage.TakeDamage(DamageType.Brute, 10);
+                }
+            }
+
+            // Stop colliding with mobs, this mimics not having enough velocity to do damage
+            // after impacting the first object.
+            // For realism this should actually be changed when the velocity of the object is less than a threshold.
+            // This would allow ricochets off walls, and weird gravity effects from slowing the object.
+            if (collidedwith.Count > 0 && Owner.TryGetComponent(out ICollidableComponent body))
+            {
+                body.CollisionMask &= (int) ~CollisionGroup.Mob;
+
+                // KYS, your job is finished.
+                Owner.RemoveComponent<ThrownItemComponent>();
+            }
+        }
+    }
+}