Implemented vehicle hooks (some changes will still be made).

src/main/java/org/bukkit/event/vehicle/VehicleEntityCollisionEvent.java

@@ -0,0 +1,22 @@
+package org.bukkit.event.vehicle;
+
+import org.bukkit.Entity;
+import org.bukkit.Vehicle;
+
+/**
+ * Raised when a vehicle collides with an entity.
+ * 
+ * @author sk89q
+ */
+public class VehicleEntityCollisionEvent extends VehicleCollisionEvent {
+    private Entity entity;
+    
+    public VehicleEntityCollisionEvent(Type type, Vehicle vehicle, Entity entity) {
+        super(type, vehicle);
+        this.entity = entity;
+    }
+    
+    public Entity getEntity() {
+        return entity;
+    }
+}